When I type
C-c C-v to see the list of TODOs, or
C-c / m to see headlines with a certain tag, org-mode shows me a sparse tree with the results.
How do I then go back to seeing the tree the way it was before I issued this command? Note that I haven't changed the file in any way, so this isn't your normal "undo", it's about going back to how org-mode was displaying the tree before.