Hur man använder Aggregate i mongoose

Prova detta

Contacts.aggregate({$group: { "_id": { code: "$Code", name: "$Name" } } }, function(err, contacts) {
   ...
});

Eller med $match om du behöver denna AgencyTranslation: /^BROADCASTING/ skick

Contacts.aggregate([
  { $match : { AgencyTranslation: /^BROADCASTING/ } },
  { $group: { "_id": { code: "$Code", name: "$Name" } } }
], function(err, contacts) {
  // ...
});