[{"user_id":1,"lead_id":901,"filed":"a"},{"user_id":2,"lead_id":902,"filed":"b"},{"user_id":2,"lead_id":903,"filed":"c"},{"user_id":3,"lead_id":999,"filed":"d"},]

db.collection.aggregate([{"$match":{"$or":[{"user_id":1,"lead_id":901},{"user_id":2,"lead_id":902}]}}])