Database
[{"Name":"Joe Doe","WentTo":[{"Destination":{"City":"Tirana","Country":"Albania"}},{"Destination":{"City":"Bari","Country":"Italy"}},{"Destination":{"City":"Pisa","Country":"Italy"}}]},{"Name":"Jane Doe","WentTo":[{"Destination":{"City":"Perth","Country":"Australia"}},{"Destination":{"City":"Bern","Country":"Switzerland"}},{"Destination":{"City":"Rome","Country":"Italy"}}]}]
Query
db.collection.aggregate([{$unwind:"$WentTo"},{$match:{"WentTo.Destination.Country":"Italy"}},{$group:{_id:"$Name","Times in Italy":{$sum:1}}}])