[{"_id":ObjectId("61e14ce9d1cb1903c6158068"),"quesOne":1,"quesTwo":2,"quesThree":3,"quesFour":2,"quesFive":2,"quesSix":3,"quesSeven":1,"quesEight":4,"quesNine":3,"quesTen":4},{"_id":ObjectId("61dfd0e0d1cb196f0b9473da"),"quesOne":2,"quesTwo":2,"quesThree":4,"quesFour":2,"quesFive":4,"quesSix":3,"quesSeven":4,"quesEight":4,"quesNine":3,"quesTen":4}]

db.collection.aggregate([{$match:{"_id":ObjectId("61e14ce9d1cb1903c6158068")}},{$project:{_id:0}},{$project:{arr:{"$objectToArray":"$$ROOT"}}},{"$unwind":"$arr"},{$group:{_id:"$arr.v",count:{$sum:1}}}])