CommandingMenuFromSplitView.xaml

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        
        <SplitView x:Name="CommandingMenu">
            <SplitView.Pane>
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="100"></RowDefinition>
                        <RowDefinition Height="*"></RowDefinition>
                    </Grid.RowDefinitions>
                    <StackPanel Grid.Row="1" Spacing="10" Margin="16">
                        <Button Content="Command 1"></Button>
                        <Button Content="Command 2"></Button>
                        <Button Content="Command 3"></Button>
                        <Button Content="Command 4"></Button>
                    </StackPanel>
                </Grid>
            </SplitView.Pane>
        </SplitView>

        <ToggleButton VerticalAlignment="Top" Margin="16" IsChecked="{x:Bind CommandingMenu.IsPaneOpen, Mode=TwoWay}">
            <FontIcon FontFamily="Segoe MDL2 Assets" Margin="16"
                              FontSize="16"
                              Glyph="&#xE700;"/>
        </ToggleButton>
    </Grid>

CommandMenuFromNavView.xaml

<Page
    x:Class="App1.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App1"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:controls="using:Microsoft.Toolkit.Uwp.UI.Controls"
    mc:Ignorable="d">
    <Page.Resources>
        <Style x:Key="NavigationViewItemStyle1" TargetType="NavigationViewItem">
            <Setter Property="Foreground" Value="{ThemeResource NavigationViewItemForeground}"/>
            <Setter Property="Background" Value="{ThemeResource NavigationViewItemBackground}"/>
            <Setter Property="BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrush}"/>
            <Setter Property="BorderThickness" Value="{StaticResource NavigationViewItemBorderThickness}"/>
            <Setter Property="UseSystemFocusVisuals" Value="True"/>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="NavigationViewItem">
                        <Grid x:Name="LayoutRoot" Background="{TemplateBinding Background}" Height="40" Control.IsTemplateFocusTarget="True">
                            <VisualStateManager.VisualStateGroups>
                                <VisualStateGroup x:Name="PointerStates">
                                    <VisualState x:Name="Normal"/>
                                    <VisualState x:Name="PointerOver">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.(RevealBrush.State)" Value="PointerOver"/>
                                            <Setter Target="LayoutRoot.Background" Value="{ThemeResource NavigationViewItemBackgroundPointerOver}"/>
                                            <Setter Target="RevealBorder.BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrushPointerOver}"/>
                                            <Setter Target="ContentPresenter.Foreground" Value="{ThemeResource NavigationViewItemForegroundPointerOver}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                    <VisualState x:Name="Pressed">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.(RevealBrush.State)" Value="Pressed"/>
                                            <Setter Target="LayoutRoot.Background" Value="{ThemeResource NavigationViewItemBackgroundPressed}"/>
                                            <Setter Target="RevealBorder.BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrushPressed}"/>
                                            <Setter Target="ContentPresenter.Foreground" Value="{ThemeResource NavigationViewItemForegroundPressed}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                    <VisualState x:Name="Selected">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.Background" Value="{ThemeResource NavigationViewItemBackgroundSelected}"/>
                                            <Setter Target="RevealBorder.BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrushSelected}"/>
                                            <Setter Target="ContentPresenter.Foreground" Value="{ThemeResource NavigationViewItemForegroundSelected}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                    <VisualState x:Name="PointerOverSelected">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.(RevealBrush.State)" Value="PointerOver"/>
                                            <Setter Target="LayoutRoot.Background" Value="{ThemeResource NavigationViewItemBackgroundSelectedPointerOver}"/>
                                            <Setter Target="RevealBorder.BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrushSelectedPointerOver}"/>
                                            <Setter Target="ContentPresenter.Foreground" Value="{ThemeResource NavigationViewItemForegroundSelectedPointerOver}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                    <VisualState x:Name="PressedSelected">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.(RevealBrush.State)" Value="Pressed"/>
                                            <Setter Target="LayoutRoot.Background" Value="{ThemeResource NavigationViewItemBackgroundSelectedPressed}"/>
                                            <Setter Target="RevealBorder.BorderBrush" Value="{ThemeResource NavigationViewItemBorderBrushSelectedPressed}"/>
                                            <Setter Target="ContentPresenter.Foreground" Value="{ThemeResource NavigationViewItemForegroundSelectedPressed}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                </VisualStateGroup>
                                <VisualStateGroup x:Name="DisabledStates">
                                    <VisualState x:Name="Enabled"/>
                                    <VisualState x:Name="Disabled">
                                        <VisualState.Setters>
                                            <Setter Target="LayoutRoot.Opacity" Value="{ThemeResource ListViewItemDisabledThemeOpacity}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                </VisualStateGroup>
                                <VisualStateGroup x:Name="PaneStates">
                                    <VisualState x:Name="NotClosedCompact"/>
                                    <VisualState x:Name="ClosedCompact">
                                        <VisualState.Setters>
                                            <Setter Target="RevealBorder.HorizontalAlignment" Value="Left"/>
                                            <Setter Target="RevealBorder.Width" Value="{Binding CompactPaneLength, RelativeSource={RelativeSource Mode=TemplatedParent}}"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                </VisualStateGroup>
                                <VisualStateGroup x:Name="IconStates">
                                    <VisualState x:Name="IconVisible"/>
                                    <VisualState x:Name="IconCollapsed">
                                        <VisualState.Setters>
                                            <Setter Target="IconBox.Visibility" Value="Collapsed"/>
                                            <Setter Target="IconColumn.Width" Value="16"/>
                                        </VisualState.Setters>
                                    </VisualState>
                                </VisualStateGroup>
                            </VisualStateManager.VisualStateGroups>
                            <Grid HorizontalAlignment="Left" VerticalAlignment="Center">
                                <Rectangle x:Name="SelectionIndicator" Fill="{ThemeResource NavigationViewSelectionIndicatorForeground}" Height="24" Opacity="0.0" Width="6" Visibility="Collapsed"/>
                            </Grid>
                            <Border x:Name="RevealBorder" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}"/>
                            <Grid HorizontalAlignment="Left" Height="40">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition x:Name="IconColumn" Width="48"/>
                                    <ColumnDefinition Width="*"/>
                                </Grid.ColumnDefinitions>
                                <Viewbox x:Name="IconBox" Child="{TemplateBinding Icon}" Margin="16,12"/>
                                <ContentPresenter x:Name="ContentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentTransitions="{TemplateBinding ContentTransitions}" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                            </Grid>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Page.Resources>

    <Grid>
    <NavigationView>
        <NavigationView.MenuItems>
            <NavigationViewItemHeader Content="Commands"/>
            <NavigationViewItem Style="{StaticResource NavigationViewItemStyle1}" x:Uid="AppsNavItem" Icon="AllApps" Content="Command 1" Tag="apps"/>
                <NavigationViewItem Style="{StaticResource NavigationViewItemStyle1}" x:Uid="GamesNavItem" Icon="Video" Content="Command 2" Tag="games"/>
                <NavigationViewItem Style="{StaticResource NavigationViewItemStyle1}" x:Uid="MusicNavItem" Icon="Audio" Content="Command 3" Tag="music"/>
        </NavigationView.MenuItems>
    </NavigationView>
    </Grid>
</Page>