[{"id":"A","name":"Meades Park","evses":[{"uid":"B","connectors":[{"id":"C","standard":"IEC_62196_T1","last_updated":ISODate("2021-02-18T23:54:56.000Z")}],"last_updated":ISODate("2021-02-18T23:54:56.000Z")},{"uid":"D","connectors":[{"id":"E","standard":"IEC_62196_T1","last_updated":ISODate("2021-02-18T23:54:56.000Z")}],"last_updated":ISODate("2021-02-18T23:54:56.000Z")}],"last_updated":ISODate("2021-12-14T23:42:06.000Z")},{"id":"F","name":"5th Avenue","last_updated":ISODate("2022-01-12T13:12:01.000Z")}]

db.collection.aggregate([{$addFields:{last_updated:{$dateToString:{format:"%Y-%m-%dT%H:%M:%SZ",date:"$last_updated"}},evses:{$map:{input:"$evses",as:"evse",in:{$mergeObjects:["$$evse",{last_updated:{$dateToString:{format:"%Y-%m-%dT%H:%M:%SZ",date:"$$evse.last_updated"}}},{connectors:{$map:{input:"$$evse.connectors",as:"connector",in:{$mergeObjects:["$$connector",{last_updated:{$dateToString:{format:"%Y-%m-%dT%H:%M:%SZ",date:"$$connector.last_updated"}}}]}}}}]}}}}}])