Merge duplicate array of objects (2d array)

I was trying to merge the 2d array which has similar element in it.

let result = [
  [
    { position: '00', symbol: 'AA' },
    { position: '01', symbol: 'AA' },
    { position: '02', symbol: 'AA' },
  ],
  [
    { position: '30', symbol: 'BB' },
    { position: '31', symbol: 'AA' },
    { position: '32', symbol: 'AA' },
  ],
  [
    { position: '00', symbol: 'AA' },
    { position: '10', symbol: 'AA' },
  ],
];

each of array might have different length

OUTPUT should be:

[
  [
    { position: '00', symbol: 'AA' },
    { position: '01', symbol: 'AA' },
    { position: '02', symbol: 'AA' },
    { position: '10', symbol: 'AA' },
  ],
  [
    { position: '30', symbol: 'BB' },
    { position: '31', symbol: 'AA' },
    { position: '32', symbol: 'AA' },
  ],
];

Explanation: position '00' exists two times so, that particular array merged with first one and after merge loop will again start from 0 to check other duplicates and merge until finish all.

UPDATE

Somehow I have managed to get expected output but Time complexity is really high. need to optimize. Please help if anyone have some optimized solution

This is my code which gave exact same result

for (let i = 0; i < result.length - 1; i++) {
    for (let j = 0; j < result[i].length; j++) {
      for (let k = i; k < result.length - 1; k++) {
        for (let l = 0; l < result[k + 1].length; l++) {
          if (result[i][j].position === result[k + 1][l].position) {

            //merge touching array
            result[i] = result[i].concat(result[k + 1]);

            //remove duplicate value
            result[i] = [
              ...new Map(
                result[i].map((m: any) => [m.position, m])
              ).values(),
            ];
            result[k + 1] = [];
            i = 0;
            j = 0;
            k = i;
            l = 0;
          }
        }
      }
    }
  }

  //remove empty array
  result = result.filter(function (bl) {
    return bl.length !== 0;
  });

  return result;