Tente isso
Contacts.aggregate({$group: { "_id": { code: "$Code", name: "$Name" } } }, function(err, contacts) {
...
});
Ou, com
$match
se você precisar desta AgencyTranslation: /^BROADCASTING/
doença Contacts.aggregate([
{ $match : { AgencyTranslation: /^BROADCASTING/ } },
{ $group: { "_id": { code: "$Code", name: "$Name" } } }
], function(err, contacts) {
// ...
});