In Discover I can select Installed or I can select Office. How do I see all installed office programs?
You seem to need to select “Installed” first, then search for “Office”.
Yes, it would be nice if you could start with the search, then switch between Home, installed, and Updates instead of clearing the search field.
This might be worth a bug report, unless there is one already. I don’t see one with a very quick glance.
The “Installed” page doesn’t have grouping yet. This is the Bugzilla ticket tracking that: https://bugs.kde.org/show_bug.cgi?id=423344.
you can just use the applications menu to see what packages are installed by category.
you can even choose uninstall or manage from the application menu by using right click which will take you directly to that package’s discover page.