[{"_id":1,"mixerId":1,"mixerName":"Tejuino","mixerType":"1","price":0,"isActive":1},{"_id":2,"mixerId":1,"mixerName":"Izze","price":0,"mixerType":"1","isActive":1},{"_id":3,"mixerId":2,"mixerName":"REGULAR SODA","mixerType":"2","price":0,"isActive":1},{"_id":4,"mixerId":2,"mixerName":"Fanta Grape","mixerType":"2","price":0,"isActive":1},{"_id":5,"mixerId":3,"mixerName":"GIN & BITTER LEMON","mixerType":"3","price":0,"isActive":1}]

db.collection.aggregate([{$group:{_id:"$mixerType",v:{$push:"$$ROOT"}}},{$project:{k:{$switch:{branches:[{case:{$eq:["1","$_id"]},then:"juices"},{case:{$eq:["2","$_id"]},then:"soda"}],default:"Others"}},_id:0,"v":1}},{$project:{data:{$arrayToObject:[["$$ROOT"]]}}},{$replaceRoot:{newRoot:"$data"}}])