Sådan bruges Aggregate i mongoose

Prøv dette

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

Eller med $match hvis du har brug for denne AgencyTranslation: /^BROADCASTING/ tilstand

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