[{"_id":1,"arry":[{"f1":"red","f2":"left"},{"f1":"blue","f2":"up"}]},{"_id":2,"arry":[{"f1":"red","f2":"right"},{"f1":"green","f2":"left"}]},{"_id":3,"arry":[{"f1":"yellow","f2":"right"},{"f1":"blue","f2":"up"}]},{"_id":4,"arry":{"f1":"red","f2":"left"}}]

db.collection.find({"arry":{"$elemMatch":{"f1":"red","f2":"left"}}})