When I try to add an action to Add a tag that is within a tag tree, none of those "sub-tags" show up. If I have to move all sub-tags that I have up to the top level in order to make this work, this will be a real pain to administer.
I can imagine that it is a pain. Can you please add this issue to the CiviRules repository at https://github.com/CiviCooP/org.civicoop.civirules/issues?
Are you able to solve this yourself (do you have PHP skills)? There is documentation on how to add your own condition here: https://docs.civicrm.org/civirules/en/latest/create-your-own-condition/. Fixing one will follow the same pattern.
If not, the usual community thing comes up:
- if the problem is big for you, it might be worth hiring someone familiar with CiviRules to fix it for you
- if the problem is not big for you wait until it is important to someone else and it is fixed