How to do nested pagination on mongoDB aggregation - node.js

Question

I have 3 main collections
Blogs{
id,
title
}
Comments{
id,
message,
blog_id
}
Likes{
id,
user_id,
blog_id
}
I want to fetch blogs, their comments, and likes altogether. Comments should come in pagination 5 at a time and blog posts are also paginated so also keep in mind that User might just want more comments to show and not Blog posts. So how to paginate comments without affecting blog's array?
Expected output:
{
_id: "POST_ID"
title: "STRING",
comments: [
{
commentMessage: "",
userName: ""
},
{
commentMessage: "",
userName: ""
}
]
}
Sample Document:
{
"_id": "5f987b80811aa021ecce5566",
"title": "nodejs2",
"comments": [
{
"commentMessage": "this is comment message 2",
"userName": "user2",
"createdTime": 123456789
},
{
"commentMessage": "this is comment message 3",
"userName": "user2",
"createdTime": 124456789
},
{
"commentMessage": "this is comment message 6",
"userName": "user2",
"createdTime": 123456789
}
]
},
I have got the expected output but unable to figure out where would I put $skip and $limit for comment's array.
Here is my sample code, the question is where should I put $skip and $limit to paginate comments
BlogPost.aggregate([
{ $match: { $or: [{ title: req.body.title }, { tags: req.body.tag }] } },
{
$lookup: {
from: PostComment.collection.name,
localField: "_id",
foreignField: "postId",
as: "comments"
},
},
{
$lookup: {
from: PostLike.collection.name,
localField: "_id",
foreignField: "postId",
as: "blog_like"
}
},
{
$lookup: {
from: User.collection.name,
localField: "comments.userId",
foreignField: "_id",
as: "UserDetail",
},
},
{
$unwind: "$UserDetail"
},
{
$project:
// working code, not an issue
},
{ $skip: 5}, // for blogs <=========== if this is wrong, let me know
{ $limit: 5} // for blogs <=========== if this is wrong, let me know
]).exec((err, blogs) => {
if (err) throw err
console.log("blogs: ", blogs)
return res.send(blogs)
})