我需要通过userrelavance集合对供稿运行查找查询

我想要实现的是：

1. 我需要在供稿列表中显示用户的相关供稿
2. 相关的供稿应按created_at进行排序，并考虑userreleavance集合中的所有用户ID。
3. 我需要保留一个极限值和偏移值，以便可以对我的相关供稿进行分页
4. 查找中的内容应按created_at（时间戳记）排序获取

下面是我的Mongo集合和架构

Feed数据：

    [
        {
            created_by:12,company_id:1,message:"Hi there"
            created_at:timestamp
        },{
            created_by:12,message:"how are you"
            created_at:timestamp
        }
        {
            created_by:13,message:"Hi",created_at:timestamp,},{
            created_by:13,message:"test",{
            created_by:14,created_at:timestamp
        }
    ]

    userrelavance :

    {
     forUser:"10",userids:[12,13]
    }

我正在执行以下查询：

    db.getcollection('userrelavance').aggregate(
    [
        {"$unwind":"$userids"},{
            $lookup:{
                from:'feeds',as:'feedObjects',let:{indicator_id:'$userids'},pipeline:[
                    {$match:{$expr:{$eq:['$created_by','$$indicator_id']}}},{$limit:2}
                ]
            }
        }
    ])

正在获取结果，但在userids（存储在relavance集合中）数组中为每个用户提供2个feed对象，但我需要2个feed对象，按created_at排序，同时考虑到所有userids记录

预期：仅考虑所有用户ID的2个提要对象，然后对created_at进行排序

已获取：

    {
        "_id" : ObjectId("5ddfc086782e53f39346b439"),"userids" : 12,"feedObjects" : [ 
            {
                "_id" : ObjectId("5d285ae2f44e3b584bf9205c"),"tags" : [ 
                    1400
                ],"message": "Hi there","company_id" : 1,"feed_type" : "post","status" : 1,"last_activity_date" : "1550839447440"
            },{
                "_id" : ObjectId("5d285ae2f44e3b584bf9205d"),"message":"How are you?"
                "company_id" : 1,"feed_type" : "greeting","last_activity_date" : "34534534534534534534534"
            },]
    },{
        "_id" : ObjectId("5ddfc086782e53f39346b439"),"userids" : 13,"feedObjects" : [ 
            {
                "_id" : ObjectId("5d285ae2f44e3b584bf9205e"),"last_activity_date" : "34345345345345"
            },{
                "_id" : ObjectId("5d285ae2f44e3b584bf9205f"),"last_activity_date" : "345435345345345"
            },]
    }