Database
db={"cities":[{"Name":"Istanbul"},{"Name":"Ankara"},{"Name":"Izmir"},{"Name":"Eskisehir"}],"dates":[{"_id":"Turkey","dateTime":"2021-09-03 10:25"},{"_id":"England","dateTime":"2021-09-03 08:25"}]}
Query
db.dates.aggregate([{"$lookup":{"from":"cities","pipeline":[],"as":"Cities"}},{$match:{_id:"Turkey"}},{"$addFields":{_id:"$$REMOVE","Country":"Turkey"}}])