Ability to nest one space under/within another. For example, a “work” space that would also include sub-spaces for “Project A,” “Project B,” etc. This is a fairly typical feature for most other notetaking and knowledge management app.
At least two reasons why this is needed…
Make it much easier to organize/navigate the list of spaces, especially if you can collapse/expand the display of sub-spaces within each parent. Especially necessary once you get rid of tags, because right now with spaces + tags you at least can have a shorter list of the top-level spaces and not worry that the much longer list of different tags clutters everything up.
Automatically associate a page (or annotation) with both the parent and sub-space, so that it will come up in search results for either. Using above example, if a page gets put in “Work/Project A” then it allows us to search either for pages specific to “Project A” or all pages within the larger “Work” space (including other sub-spaces).
(For #2, I suppose in theory I could just separately put a page in both the “Work” and “Project A” spaces. But this is a waste of time/effort, and also requires me to remember my own scheme of associated spaces. And when I inevitably forget to do this for some pages, then the search results will be inconsistent/unreliable.)