I have database model

```
Schema({
  members: [
    {
      type: String,
      required: true,
      ref: "User"
    }
  ],
  createdAt: {
    type: Date,
    default: Date.now(),
    required: true
  },
  lastMessage: {
    message: {
      type: String,
      required: true
    },
    from: {
      type: String,
      required: true
    },
    createdAt: {
      type: Date,
      required: true
    }
  },
  messages: [
    {
      createdAt: {
        type: Date,
        required: true
      },
      message: {
        type: String,
        required: true
      },
      from: {
        type: String,
        ref: "User",
        required: true
      }
    }
  ]
});

```

That code I use to find some documents

```
Chats.countDocuments(
      {
        members: {
          $in: ["userIdOne", "userIdTwo"]
        }
      },
      cb
    )

```

I use `$in` to find data what I need, but `$in` find all documents which contains one of this **userId...**. Me need to find only one document which contains that user's ids.

How can i do this?