db={"users":[{"user":{"_id":"d10430c8-e59","username":"John","password":"f7wei93","location":"UK","gender":"Male","age":26,"socials":[{"type":"instagram","maleFollowers":23000,"femaleFollowers":65000,"posts":5400,"avgFollowerAge":22},{"type":"facebook","maleFollowers":4000,"femaleFollowers":6700,"posts":330,"avgFollowerAge":25},{"type":"snapchat","maleFollowers":873,"femaleFollowers":1200,"posts":1200,"avgFollowerAge":21},]}}]}

db.users.aggregate([{$unwind:"$user.socials"},{$group:{_id:{user:"$user._id",type:"$user.socials.type"},"totalFollowersCount":{$sum:{$add:["$user.socials.femaleFollowers","$user.socials.maleFollowers"]}}}},{$match:{"_id.type":{$in:["instagram","snapchat"]}}}])