[{"_id":1,"subject":"History","score":88},{"_id":2,"subject":"History","score":92},{"_id":3,"subject":"History","score":97},{"_id":4,"subject":"History","score":71},{"_id":5,"subject":"History","score":79},{"_id":6,"subject":"History","score":83}]

db.collection.aggregate([{$facet:{data:[{$match:{score:{$gt:80}}},{$skip:0},{$limit:2},{"$project":{score:1}}],}},])