[{_id:ObjectId("616efd7e56c9530018e318ac"),student:{name:"Alpha",email:null,nisn:"0408210001",gender:"female"}},{_id:ObjectId("616efd7e56c9530018e318af"),student:{name:"Beta",email:null,nisn:"0408210001",gender:"male"}}]

db.collection.aggregate([{$group:{_id:0,data:{$push:{_id:"$_id",student:"$student"}}}},{$unwind:{path:"$data",includeArrayIndex:"no",}},{"$project":{"_id":0,"id":"$data._id","name":"$data.student.name","nisn":"$data.student.nisn",no:{"$add":["$no",1]}}}])