我正在尝试弄清楚如何按值对集合进行排序,其中另一个值==为其他值,请参阅下面的文档{"_id":"zLFp8KptxzACGtAZj","createdAt":"2015-05-28T21:11:57.044Z",..."profile":{"firstname":"Nelle","lastname":"Carroll",..."services":[{"serviceId":"Gy7uptfk8LNWMgEQy","rate":19},{"serviceId":"KvFETNLK8cJ78e6gy","rate":1},{"serviceId":"xwY532yxcWQ7qAjuP"