Database
db={imageEvent:[{_id:"ObjectId(6246ab45e95eac6c85726cfc)",imageName:"IMG_123456.jpg",eventTime:"2022-04-01T07:35:30.615Z",deviceId:"48701ED21819"},{_id:"ObjectId(6246ab45e95eac6c85726cfd)",imageName:"IMG_123456.jpg",eventTime:"2022-04-01T07:38:10.543Z",deviceId:"58701ED21819"},{_id:"ObjectId(6246ab45e95eac6c85726cfe)",imageName:"IMG_123456.jpg",eventTime:"2022-04-01T08:05:50.865Z",deviceId:"48701ED21819"}]}
Query
db.imageEvent.aggregate([{$sort:{eventTime:-1}},{"$group":{"_id":{"deviceId":"$deviceId"},data:{$push:"$$ROOT"}}},{"$replaceRoot":{"newRoot":{$first:"$data"}}}])