Mongoose module get nested array from specific document. | NestJS | Page 1

I am trying to retriev an array from a mongoose schema usging the aggragate function fron mongoose.

    const notifications = await this.userRepo.aggregate( [
          { $match: { _id: userId } },
          { $unwind: "$notifications" },
          { $replaceRoot: { newRoot: '$notifications' } }
    ] );

The problem here is that every time I am getting an empty array. No matter what is inside the document.

Here is a document example:

    {
      _id: new ObjectId("6471fe4a0045e48a0c6193ba"),
      gateways: [
        {
          _id: '5231db1f-b79a-4dc3-a387-6f08ad7b6857',
          name: 'Babylon Dev',
          right: 'owner'
        }
      ],
      __v: 0,
      notifications: [
        {
          type: 'confirm',
          title: 'Gateway whitelist request!',
          description: '6471fe4a0045e48a0c6193ba wants to share data from gateway 5231db1f-b79a-4dc3-a387-6f08ad7b6857 with you.',
          actions: [Array],
          from: '6471fe4a0045e48a0c6193ba',
          subject: '5231db1f-b79a-4dc3-a387-6f08ad7b6857',
          status: 'unread',
          _id: new ObjectId("64b6791adbf7bb6eaa528cf2")
        }
      ]
    }

Can someone clue me in where am I setting this up wrong?

The result that I want is to get the notifications array:

    [
        {
          type: 'confirm',
          title: 'Gateway whitelist request!',
          description: '6471fe4a0045e48a0c6193ba wants to share data from gateway 5231db1f-b79a-4dc3-a387-6f08ad7b6857 with you.',
          actions: [Array],
          from: '6471fe4a0045e48a0c6193ba',
          subject: '5231db1f-b79a-4dc3-a387-6f08ad7b6857',
          status: 'unread',
          _id: new ObjectId("64b6791adbf7bb6eaa528cf2")
        }
      ]

Also it would help to get/update/delete one element inside the notifications array.

#Mongoose module get nested array from specific document.