It would be great if jolpin could group tags under other parent tags, similar to getting things gnome. It would make tagging notes and tasks even more powerful.
This feature was tried a while back, but removed due to performance issues. I'm sure that it will reappear again at some point in the future.
You can do it manually by creating
Tag1:Sub1 Tag1:Sub2 Tag1:Sub3
But there are many many threads here discussing this. Plz do a search and maybe you can find them.
this is something I also miss greatly.