How can i join 3 collection with aggregation? - node.js

Question

Here is my structure
country
[
{
"studentid": [
"5bb482fdac231f1354c47aab"
],
"_id": "5bb672fb92c98117d004c733",
"name": "china",
"__v": 0
}
]
users
[
{
"books": [
"5bb657ea05bf6d0ef096e529",
"5bb6580d05bf6d0ef096e52a"
],
"_id": "5bb482fdac231f1354c47aab",
"firstName": "will",
"lastName": "smith",
"email": "user3#gmail.com",
"address": "rajkot",
"salary": 5000,
"department": "electrical",
"__v": 0
}
]
books
[
{
"_id": "5bb657ea05bf6d0ef096e529",
"name": "book 1",
"price": 100,
"pages": 200,
"__v": 0
}
]
Now i am trying to join this 3 collections each array wise
Here is code that i tried
CountryModel.aggregate([
{ $match: { name: country } },
{
$lookup: {
from: UserModel.collection.name,
let: { student_id: "_id" },
pipeline: [
{ "$match": { "_id": "$student_id" } },
{
$lookup: {
from: UserModel.collection.name,
let: { book_id: "$books" },
pipeline: [
{
$lookup: {
from: BookModel.collection.name,
let: { bookid: "$_id" },
pipeline: [
{ "$match": { "$expr": { "$in": ["$book_id", "$bookid"] } } },
],
as: "more"
}
}
],
as: "books"
}
}
],
as: "studentid"
},
},
])
can someone tell me were i am doing wrong ?