[{"_id":"act_8347100017075469","firstName":"Akki","lastName":"Dlast","accountNumber":"12397124","feature":{"feature-name1":{"baseCode":"bc1","serviceCode":[/**numb of elements & name of elements in servicesCodes are dynamic*/"SC1","SC2","SC3"]},"feature-name2":{"baseCode":"bc2","serviceCode":[/**numb of elements & name of elements in servicesCodes are dynamic*/"SC21","SC22"]},"feature-name3":{"baseCode":"bc3","serviceCode":["SC41","SC42","SC43"]}}}]

db.collection.aggregate([{"$set":{"feature":{"$objectToArray":"$feature"}}},{"$unwind":"$feature"},{"$unwind":"$feature.v.serviceCode"},{"$sort":{"accountNumber":1,"feature.k":1,"feature.v.baseCode":1,"feature.v.serviceCode":1}},{"$project":{"_id":0,"Account No":"$accountNumber","feature-name":"$feature.k","base-code":"$feature.v.baseCode","svc-code":"$feature.v.serviceCode"}}])