Check out the video demo at the bottom

IndicatorRecyclerView.java

package catvinhquang.androiddeveloper;

import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;

import catvinhquang.androiddeveloper.Utils;

/**
 * Created by Quang Cat on 25-Jun-2019
 **/

public class IndicatorRecyclerView extends RecyclerView {
    private int indicatorColor = 0xff0288D1;
    private int indicatorHeight = Utils.dpToPx(2);
    private int indicatorPosition = 0;
    private int indicatorLeft;
    private Paint paint;
    private ValueAnimator animator;

    public IndicatorRecyclerView(Context context) {
        super(context);
        init();
    }

    public IndicatorRecyclerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public IndicatorRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(indicatorColor);
        animator = new ValueAnimator();
        animator.addUpdateListener(animation -> {
            indicatorLeft = (int) animation.getAnimatedValue();
            invalidate();
        });
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(canvas);

        ViewHolder vh = findViewHolderForLayoutPosition(indicatorPosition);
        if (vh != null) {
            int l = animator.isRunning() ? indicatorLeft : vh.itemView.getLeft();
            int t = getHeight() - indicatorHeight;
            int r = l + vh.itemView.getWidth();
            int b = getHeight();
            canvas.drawRect(l, t, r, b, paint);
        }
    }

    public void setIndicatorPosition(int position) {
        if (indicatorPosition == position) {
            return;
        }

        ViewHolder h1 = findViewHolderForLayoutPosition(indicatorPosition);
        ViewHolder h2 = findViewHolderForLayoutPosition(position);

        if (h1 != null && h2 != null) {
            int start = h1.itemView.getLeft();
            int end = h2.itemView.getLeft();
            if (animator.isRunning()) {
                animator.cancel();
            }
            animator.setIntValues(start, end);
            animator.start();
        }

        indicatorPosition = position;
        smoothScrollToPosition(position);
        invalidate();
    }
    
    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (animator.isRunning()) {
            animator.cancel();
        }
    }
}