How to get data from 3rd collection on the basis of 2nd collection relation with first collection in Laravel Mongodb database?

Question

I have 1st collection of users:

{
  "_id": {
    "$oid": "5ed0f5bf815f000004006fa5"
  },
  "name": "admin",
  "email": "admin@admin.com",
  "password": "$2y$10$JxLj.sPQ.WLwE7cVHTIY3OYSar9B2OjxDzS1uQJwVmMug3mipHMVS",
  "updated_at": {
    "$date": "2020-06-02T07:41:23.052Z"
  },
  "created_at": {
    "$date": "2020-05-29T11:45:03.136Z"
  },
  "book_ids": [
    "5ed0f3efcb4b0000c500462b"
  ]
}

2nd collection books:

[
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c500462b"
    },
    "name": "book",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.502Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.502Z"
    },
    "chapter_ids": [
      "5ed0f3efcb4b0000c5004622",
      "5ed0f3efcb4b0000c5004623",
      "5ed0f3efcb4b0000c5004624",
      "5ed0f3efcb4b0000c5004625",
      "5ed0f3efcb4b0000c5004626",
      "5ed0f3efcb4b0000c5004627",
      "5ed0f3efcb4b0000c5004628",
      "5ed0f3efcb4b0000c5004629",
      "5ed0f3efcb4b0000c500462a"
    ],
    "user_ids": [
      "5ed0f5bf815f000004006fa5"
    ]
  }
]

3rd collection chapters:

  [
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004622"
    },
    "name": "users manage",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.488Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.488Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004623"
    },
    "name": "role list",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.491Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.491Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004624"
    },
    "name": "role create",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.492Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.492Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004625"
    },
    "name": "role edit",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.493Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.493Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004626"
    },
    "name": "role delete",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.494Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.494Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004627"
    },
    "name": "item list",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.495Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.495Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004628"
    },
    "name": "item create",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.497Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.497Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c5004629"
    },
    "name": "item edit",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.498Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.498Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  },
  {
    "_id": {
      "$oid": "5ed0f3efcb4b0000c500462a"
    },
    "name": "item delete",
    "guard_name": "web",
    "updated_at": {
      "$date": "2020-05-29T11:37:19.499Z"
    },
    "created_at": {
      "$date": "2020-05-29T11:37:19.499Z"
    },
    "book_ids": [
      "5ed0f3efcb4b0000c500462b"
    ]
  }
]

I want users wise books and books chapters in single collection. Can Anyone please help me on this?

Answer 1

After all the efforts I found the solution for this:

db.collection.aggregate([
  { "$lookup": {
    "from": books,
    "localField": "book_ids",
    "foreignField": "_id",
    "as": "books"
  }},
  { "$unwind": "$books" },
  { "$lookup": {
    "from": chapters,
    "localField": "books.chapter_ids",
    "foreignField": "_id",
    "as": "books.chapters",
  }},
]}

This solution works for me hope it will works for the others too.