Database
[{"_id":{"$oid":"6296968fa63757a93e1cd123"},"Level1":{"Level2":[{"ChildId":"1234","ChildDate":ISODate("2021-04-01T04:00:00.000Z")},{"ChildId":"5678","ChildDate":ISODate("2017-05-16T04:00:00.000Z")},{"ChildId":"3456","ChildDate":ISODate("2008-09-16T04:00:00.000Z")},{"ChildDate":ISODate("2022-06-01T04:00:00.000Z"),"ChildId":"7891"}]}}]
Query
db.collection.find({"Level1.Level2":{"$elemMatch":{ChildId:"3456",ChildDate:{$gt:ISODate("2008-08-16T05:00:00.000Z")}}}})