[{empId:"123",empName:"Emp1",shiftHours:"Regular"},{empId:"123",empName:"Emp1",shiftHours:"Morning"}]

db.collection.aggregate([{$group:{_id:"$empId",empName:{$first:"$empName"},Morning:{$sum:{"$cond":{"if":{$eq:["$shiftHours","Morning"]},"then":1,"else":0}}},Regular:{$sum:{"$cond":{"if":{$eq:["$shiftHours","Regular"]},"then":1,"else":0}}},Evening:{$sum:{"$cond":{"if":{$eq:["$shiftHours","Evening"]},"then":1,"else":0}}}}},{$set:{Morning:{$cond:[{$gt:["$Morning",0]},"Y","N"]},Regular:{$cond:[{$gt:["$Regular",0]},"Y","N"]},Evening:{$cond:[{$gt:["$Evening",0]},"Y","N"]}}}])