Database
[{id:11111,up:450000,down:452000},{id:11112,up:450000,down:462000},{id:11113,up:450000,down:452000},{id:11114,up:450000,down:462000}]
Query
db.collection.aggregate([{"$project":{"updown":{"$objectToArray":{"up":"$up","down":"$down"}}}},{"$unwind":"$updown"},{"$group":{"_id":{"label":"$updown.v"},"count":{"$sum":1}}},{"$project":{"_id":0,"label":"$_id.label","count":"$count"}},{"$sort":{"label":1}},{"$match":{"count":{"$gt":0}}}])