db={"quiz_customer_record":[{"_id":ObjectId("5f6ec91cbf74d27430b9c24f"),"quiz_id":"5f3a33185a1cd35632b8c98c","user_id":"5efae8bed5c5f06f30a057ff","name":"ABC","qualification":"ttt","time_required":"0:13 Mins","questions_attempted":2,"total_quiz_questions":2,"attempt_date":"2020-09-26T04:52:48.169Z"},{"_id":ObjectId("5f6eca82bf74d27430b9c252"),"quiz_id":"5f3a33185a1cd35632b8c98c","user_id":"5f6ec9ba3b502398598a5ade","name":"Test","qualification":"BSC","time_required":"0:6 Mins","questions_attempted":2,"total_quiz_questions":2,"attempt_date":"2020-09-26T04:58:46.060Z"}],"dummy":[{"_id":ObjectId("5f16eb5f5007bd5395c76eda"),"user_id":"5f06e0ddf718c04de30ea47f","question_id":"5f05bbfb0cf3166085be68fd","quiz_id":"5f05bbd10cf3166085be68fc","selected_answer":"No data","attempt_date":"2020-07-21T13:19:29.377Z","total_marks":0,"result":true},{"_id":ObjectId("5f6ec88abf74d27430b9c249"),"user_id":"5efae8bed5c5f06f30a057ff","question_id":"5efc3c84a222c326c7b49e35","quiz_id":"5efc3ba4a222c326c7b49e33","selected_answer":["rer"],"attempt_date":"2020-09-26T04:50:21.988Z","total_marks":2,"result":true},{"_id":ObjectId("5f6ec906bf74d27430b9c24d"),"user_id":"5efae8bed5c5f06f30a057ff","question_id":"5f6ec888bf74d27430b9c248","quiz_id":"5f3a33185a1cd35632b8c98c","selected_answer":["rgdfgdfg"],"attempt_date":"2020-09-26T04:58:46.060Z","correct_answer":["rgdfgdfg"],"result":true},{"_id":ObjectId("5f6eca82bf74d27430b9c250"),"user_id":"5f6ec9ba3b502398598a5ade","question_id":"5f6ec888bf74d27430b9c248","quiz_id":"5f3a33185a1cd35632b8c98c","selected_answer":["rgdfgdfg"],"attempt_date":"2020-09-26T04:58:46.060Z","correct_answer":["rgdfgdfg"],"result":true},{"_id":ObjectId("5f6eca82bf74d27430b9c251"),"user_id":"5f6ec9ba3b502398598a5ade","question_id":"5f6ec8b4bf74d27430b9c24b","quiz_id":"5f3a33185a1cd35632b8c98c","selected_answer":["sdfsdf"],"attempt_date":"2020-09-26T04:58:46.060Z","correct_answer":["sdfsdf"],"result":true}]}

db.quiz_customer_record.aggregate([{$match:{quiz_id:"5f3a33185a1cd35632b8c98c"}},{$sort:{attempt_date:-1}},{$group:{_id:"$user_id",result1:{$first:"$attempt_date"},quiz_id:{$first:"$quiz_id"},attempt_date:{$first:"$attempt_date"},o_id:{$first:"$_id"}}},{$lookup:{from:"dummy",let:{quiz_id:"$quiz_id",user_id:"$_id",attempt_date:"$attempt_date"},pipeline:[{$match:{$expr:{$and:[{$eq:["$$quiz_id","$quiz_id"]},{$eq:["$$user_id","$user_id"]},{$eq:["$$attempt_date","$attempt_date"]}]}}}],as:"dummy"}},{$project:{_id:"$o_id",user_id:"$_id",result1:1,total_dummy_rec:{$size:"$dummy"}}}])