transactions.ts

const transactions = [
  {
    id: 3,
    sourceAccount: "A",
    targetAccount: "B",
    amount: 100,
    category: "eating_out",
    time: "2018-03-02T10:34:30.000Z",
  },
  {
    id: 1,
    sourceAccount: "A",
    targetAccount: "B",
    amount: 100,
    category: "eating_out",
    time: "2018-03-02T10:33:00.000Z",
  },
  {
    id: 6,
    sourceAccount: "A",
    targetAccount: "C",
    amount: 250,
    category: "other",
    time: "2018-03-02T10:33:05.000Z",
  },
  {
    id: 4,
    sourceAccount: "A",
    targetAccount: "B",
    amount: 100,
    category: "eating_out",
    time: "2018-03-02T10:36:00.000Z",
  },
  {
    id: 2,
    sourceAccount: "A",
    targetAccount: "B",
    amount: 100,
    category: "eating_out",
    time: "2018-03-02T10:33:50.000Z",
  },
  {
    id: 5,
    sourceAccount: "A",
    targetAccount: "C",
    amount: 250,
    category: "other",
    time: "2018-03-02T10:33:00.000Z",
  },
];

type Transaction = (typeof transactions)[0];

const transactionsGrouped = (tscts: Transaction[]) => {
  const transactionArray: Transaction[][] = [];
  tscts.forEach((tsct) => {
    const existsId = transactionArray.some((ts) =>
      ts.some((t) => t.id === tsct.id)
    );
    if (!existsId) {
      const transactionFinded = tscts.filter(
        (ts) =>
          ts.amount === tsct.amount &&
          ts.sourceAccount === tsct.sourceAccount &&
          ts.category === tsct.category &&
          ts.targetAccount === tsct.targetAccount
      );
      transactionArray.push(transactionFinded);
    }
  });

  return transactionArray;
};

console.log(transactionsGrouped(transactions));