The Academy site is not great for seeing exactly what the requirements are. As far as I know, being a "completer" for any academy means taking four classes from the list and completing a capstone project, but I could be wrong. I don't think that's a separate course, but something you complete on your own.
In the Law case, the minimum pathway seems pretty laid out already with NSL Gov, and the three required law classes with one being a prerequisite for the other two.
This thread has a post where someone describes the first law class and a forensics class (which fits in with law). Look for post at timestamp 12/10/2025 09:21
https://www.dcurbanmom.com/jforum/posts/list/15/1304933.page
In the video at the top of this Academy page the Law instructor discusses the classes:
https://sites.google.com/mcpsmd.net/mbhscoursebulletin/course-selection-process/blair-academies
I hope this helps at least somewhat. It does look like an interesting program.