db={"user":[{"_id":ObjectId("5f867e0d126ddbde24d6ee73"),"name":"Jaskson","age":"24"}],"Polls":[{"_id":ObjectId("5f87d988ddae726a3dbe5459"),"name":"RedVsWhite","total_votes":"0"},{"_id":ObjectId("5f51408ffc1d0437fa31d6f7"),"name":"ApplesVsOrange","total_votes":"0"}],"VotesRecords":[{"_id":ObjectId("5f864addddae726a3dbe53de"),"voter_id":ObjectId("5f867e0d126ddbde24d6ee73"),"poll_id":ObjectId("5f87d988ddae726a3dbe5459"),"voter_selection":"red"},{"_id":ObjectId("5f864addddae726a3dbe53df"),"voter_id":ObjectId("5f867e0d126ddbde24d6ee74"),"poll_id":ObjectId("5f87d988ddae726a3dbe5459"),"voter_selection":"red"}]}

db.Polls.aggregate([{"$lookup":{"localField":"_id","from":"VotesRecords","foreignField":"poll_id","as":"VotesRecords"}},{"$unwind":{"path":"$VotesRecords","preserveNullAndEmptyArrays":true}},{"$project":{"_id":"$_id","name":"$name","total_votes":1,"voter_selection":{$cond:[{$eq:["$VotesRecords.voter_id",ObjectId("5f867e0d126ddbde24d6ee73")]},"$VotesRecords.voter_selection","$$REMOVE"]}}},{$group:{_id:"$_id",root:{$mergeObjects:"$$ROOT"}}},{$replaceWith:"$root"}])