Lodash groupBy id of each item of nested array of object

Question

I have the following input as an example of clubs that includes a property players which is an array of objects.

Input

const clubs = [
  {
    id: 5,
    name: 'Club Name',
    creatorId: 10,
    players: [
      {
        userId: 2, // group by this property
        name: 'Player name 1',
        clubId: 5,
      },
      {
        userId: 7, // group by this property
        name: 'Player name 2',
        clubId: 5,
      },
    ],
  },
  {
    id: 6,
    name: 'Club Name 2',
    creatorId: 2,
    players: [
      {
        userId: 7, // group by this property
        name: 'Player name 3',
        clubId: 6,
      },
      {
        userId: 8, // group by this property
        name: 'Player name 4',
        clubId: 6,
      },
      {
        userId: 22, // group by this property
        name: 'Player name 5',
        clubId: 6,
      },
    ],
  },
];

I want to groupBy each of the player.userId s of each club and should have a value of the club for each player, to have the following output.

Desired Output

{
  '2': [{ id: 5, name: 'Club Name', creatorId: 10, players: [Array] }],
  '7': [
    { id: 5, name: 'Club Name', creatorId: 10, players: [Array] },
    { id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] },
  ],
  '8': [{ id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] }],
  '22': [{ id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] }],
};

I have tried

const byPlayer = allClubs.reduce((b, a) => {
  a.players.forEach((player) => {
    const id = player.clubId;
    const clubsByPlayer = b[id] || (b[id] = []);
    clubsByPlayer.push(a);
  });
  return b;
}, {});

But it returned the group by the clubId and a value of each player in the club

{
  '5': [
    { id: 5, name: 'Club Name', creatorId: 10, players: [Array] },
    { id: 5, name: 'Club Name', creatorId: 10, players: [Array] },
  ],
  '6': [
    { id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] },
    { id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] },
    { id: 6, name: 'Club Name 2', creatorId: 2, players: [Array] },
  ],
};

Answer 1

Replace

const id = player.clubId;

with

const id = player.userId;

 const clubs = [{ id: 5, name: 'Club Name', creatorId: 10, players: [{ userId: 2, name: 'Player name 1', clubId: 5 }, { userId: 7, name: 'Player name 2', clubId: 5 }] }, { id: 6, name: 'Club Name 2', creatorId: 2, players: [{ userId: 7, name: 'Player name 3', clubId: 6 }, { userId: 8, name: 'Player name 4', clubId: 6 }, { userId: 22, name: 'Player name 5', clubId: 6 }] }], byPlayer = clubs.reduce((b, a) => { a.players.forEach((player) => { (b[player.userId]??= []).push(a); }); return b; }, {}); console.log(byPlayer)

 .as-console-wrapper { max-height: 100%;important: top; 0; }