[{"batchid":1,"createdAt":"2021-09-01T11:23:25.184Z"},{"batchid":1,"createdAt":"2021-09-05T11:23:25.184Z"}]

db.collection.aggregate([{$group:{_id:"$batchid",btime:{$max:"$createdAt"},doc:{$push:"$$ROOT"}}},{$match:{btime:{$gt:"2021-07-01T11:23:25.184Z"}}}])