[{"_id":"5f30df23243ffsdfwer3d14568bf","value":{"busId":200.0,"status":{"code":{"id":1.0,"key":"2100","value":"Complete"}}}},{"_id":"5f30df23243ffsdfwer3d14568bg","value":{"busId":200.0,"status":{"code":{"id":1.0,"key":"2100","value":"Complete"}}}},{"_id":"5f30df23243ffsdfwer3d14568bh","value":{"busId":200.0,"status":{"code":{"id":1.0,"key":"2100","value":"Reject"}}}}]

db.collection.aggregate([{$addFields:{"value.available":{$cond:[{$in:["$value.status.code.value",["Accept","Complete"]]},"Approved","Rejected"]}}},{"$group":{"_id":{busID:"$value.busId",status:"$value.available"},"subtotal":{$sum:1}}},{$group:{_id:"$_id.busID",status:{$push:{k:"$_id.status",v:"$subtotal"}}}},{$project:{_id:{$mergeObjects:[{busID:"$_id"},{$arrayToObject:"$status"}]}}}])