Agree, also it would be great if you can provide fields to be used here. Because scanning the document to find the field that matches the requirement is taking lot of time and also we end up with comparing with incorrect field. The query is written correctly but to comparing with incorrect field it is messing the output of the lab graded assignment.
It would be great to provide more context around the question/feedback you have raised regarding the lab.
I see that you have already completed the lab, however, it would be great to know your thoughts for improvement. Also, we are working on revamping the aggregation course, so we welcome all user feedback.
Meanwhile, having meaningful discussions around any doubts can further improve the learning experience.