[{"machine":1,"status":true,"comments":[{"machine":1,"status":false,"emp":"158","comment":"testing the latest update"},{"machine":1,"status":false,"emp":"007","comment":"2nd comment"},{"machine":1,"status":false,"emp":"007","comment":"3rd comment"},]},{"machine":2,"status":true,"comments":[{"machine":2,"status":true,"emp":"158","comment":"checking dcm 2"}]}]

db.collection.aggregate([{$match:{"comments.machine":{$in:[1,2]},"comments.emp":"007"}},{"$addFields":{"comments":{"$filter":{"input":"$comments","as":"comment","cond":{$eq:["$$comment.emp","007"]}}}}}])