Are there any plugins to allow hierarchal organization?

[rajlego]

I’d like to be able to have notes be hierarchical and for notes to contain other notes, as in SuperMemo:

Each yellow “T” is a note and contains sub-notes. I’d like to be able to do the same in obsidian.

[PeterG]

There’s a community plugin called “Folder Note” that might work for you. It doesn’t allow nested notes per se, but it allows you to create an “index” note associated to each folder (optionally hidden from regular view). It requires an extra step or two, but it accomplishes more or less the same thing with the right settings.