Database
[{"value":{"busId":100.0,"status":{"code":{"id":1.0,"key":"2100","value":"Complete"}}}},{"value":{"busId":200.0,"status":{"code":{"id":1.0,"key":"2100","value":"Reject"}}}},{"value":{"busId":100.0,"status":{"code":{"id":1.0,"key":"2100","value":"Accept"}}}}]
Query
db.collection.aggregate([{$addFields:{"value.available":{$cond:[{$in:["$value.status.code.value",["Accept","Complete"]]},"Approved","Rejected"]}}},{"$group":{"_id":{_id:"$value.busId",status:"$value.available"},"count":{$sum:1}}}])