[{_id:1,"timestamp":"2022-11-03T10:00:00.000+00:00",score:10},{_id:2,"timestamp":"2022-11-03T09:00:00.000+00:00",score:13},{_id:3,"timestamp":"2022-11-03T10:00:00.000+00:00",score:27},{_id:4,"timestamp":"2022-11-03T10:00:00.000+00:00",score:26}]

db.collection.aggregate([{$group:{_id:0,excellent:{$sum:{$cond:[{$gte:["$score",30]},1,0]}},good:{$sum:{$cond:[{$and:[{$gte:["$score",20]},{$lt:["$score",30]}]},1,0]}},ok:{$sum:{$cond:[{$and:[{$gte:["$score",10]},{$lt:["$score",20]}]},1,0]}},poor:{$sum:{$cond:[{$lt:["$score",10]},1,0]}}}},{$unset:"_id"},{$project:{data:{$objectToArray:"$$ROOT"}}},{$project:{data:{$map:{input:"$data",in:{nmae:"$$this.k",count:"$$this.v"}}}}}])