It would be nice to have a feature to collapse all tags of xml text (or other code) to, say level 1 or level 2.
I would like to have that too!
Not exactly what requested but you can collapse a top-level fold point and expand only the next level when holding the Shift key while expanding a fold point (details at https://www.geany.org/manual/#folding).
At least, this makes it easy to expand the first and second level on one fold point manually.
Everything beyond this needs to be implemented by someone who is interested.
github-comments@lists.geany.org