db={"follow":[{"_id":1,"start":"user1","end":"user2",},{"_id":2,"start":"user2","end":"user3",}],"story":[{"_id":1,"owner_id":"user2","updated_at":1638090000,"deleted_at":null},{"_id":3,"owner_id":"user3","updated_at":1638090000,"deleted_at":null},{"_id":2,"owner_id":"user3","updated_at":1638080000,"deleted_at":null}]}

db.follow.aggregate([{"$match":{"start":"user2"}},{$lookup:{from:"story",as:"stories",localField:"end",foreignField:"owner_id",pipeline:[]}},])