How $limit will works with $group in mongodb

Question

How $limit will works with $group in mongodb

I am having several records in a information table. In which infoId can be common for several users who are involved in that.Information Collection looks like:

{
_id:ObjectId(),
infoId:001,
userName:x,
designation:xx,
year:10
},
{
_id:ObjectId(),
infoId:001,
userName:a,
designation:aa,
year:10
},
{
_id:ObjectId(),
infoId:001,
userName:y,
designation:yy,
year:3
},
{
_id:ObjectId(),
infoId:002,
userName:x,
designation:xx,
year:7
},
{
_id:ObjectId(),
infoId:003,
userName:x,
designation:xx,
year:10
},
{
_id:ObjectId(),
infoId:001,
userName:c,
designation:cc,
year:10
}....

From the information table, I want to get the records based on grouping infoId. So I can use aggregate query to get this.

db.information.aggregate([$group:{_id:$infoId,users:{$push:"$$ROOT"},$sort:{infoId:-1}]);

I will get the result like :

[{
_id:003,
users:[
    {
    _id:ObjectId(),
    infoId:003,
    userName:x,
    designation:xx,
    year:10
    }]
},
{
 _id:002,
 users:[{
    _id:ObjectId(),
    infoId:002,
    userName:x,
    designation:xx,
    year:7
    }]
},
{
  _id:001,users:[
    {
    _id:ObjectId(),
    infoId:001,
    userName:x,
    designation:xx,
    year:10
    },
    {
    _id:ObjectId(),
    infoId:001,
    userName:a,
    designation:aa,
    year:10
    },
    {
    _id:ObjectId(),
    infoId:001,
    userName:y,
    designation:yy,
    year:3
    },
    {
    _id:ObjectId(),
    infoId:001,
    userName:c,
    designation:cc,
    year:10
    }

]}

}]

But in this say I want give some limit in such way that it need to retrieve upto that only.

If I am giving say limit as 4, then it need to return _id:003, _id:002, in _id:001 only two. Note: The limit whatever specifying should not for result after grouping.

So how can I query this in mongodb?

node.js
mongodb