Hi Adam.
Versions: Win11 23H2 22631.3880 | Start11 v2 2.08
Actually, the information already made is quite sufficient for a reproduction ...
Anyway:
1. manage filtered folder

2. New - 3. set Name - 4. OK

5. select destination folder - 6. C:\Tools - 7. OK

8. include Regex rule - 9. "exe" for all EXE files (like the example [type "png" for all PNG files]) - 10. OK

11. pin Foldermenu - 12. custom filtered folde > 13. Tools

I expected that now only exe files are shown - like in the folder "Partition Wizard" these 9 files:

but unfortunately only a file with EXE in the name - and not as an extension - is displayed!

QUESTION: How to filter by extensions ?