Database
[{"admin":{"emailSentDate":"11-07-2023"}},{"admin":{"emailSentDate":"11-07-2022"}}]
Query
db.collection.aggregate([{$addFields:{"admin.emailSentDate":{$dateFromString:{dateString:"$admin.emailSentDate",format:"%d-%m-%Y"}}}},{$match:{"admin.emailSentDate":{$gte:ISODate("2023-02-15T13:29:54.064Z")}}}])