[{"empId":"101962700","Result":"NotEnrolled","enrollDate":"4/21/2021","Name":"THOMAS Edison","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}},{"empId":"101962700","Result":"NotEnrolled","enrollDate":"5/21/2021","Name":"THOMAS Edison","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}},{"empId":"101962700","Result":"NotEnrolled","enrollDate":"5/21/2021","Name":"THOMAS Edison","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}},{"empId":"101962701","Result":"Enrolled","enrollDate":"4/21/2021","Name":"Jim Miller","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}},{"empId":"101962701","Result":"Enrolled","enrollDate":"5/21/2021","Name":"Jim Miller","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}},{"empId":"101962701","Result":"Enrolled","enrollDate":"5/21/2021","Name":"Jim Miller","Flag":"NEGATIVE","createdDateTime":{"$date":"2021-06-30T06:00:00.000Z"}}]

db.collection.aggregate([{$group:{_id:{empId:"$empId",enrollDate:"$enrollDate"},data:{$first:"$$ROOT"}}},{$replaceRoot:{newRoot:"$data"}}])