Created attachment 134740 [details]
Screenshot showing difference betweeen menu editor and application launcher menus

SUMMARY

The results are not shown in the application dashboard when using kde menu editor to edit the menu structure, including adding new menus, separators and sub-menus (or folders), 

I ran kmenueditor from console, and there were no errors output. The changes simply aren't shown in the application dashboard.

This may just be a case of lack of implementation, but if so, it would nice to get a notice that these features have not been implemented yet, so we don't waste time trying to figure out why we can't organize our menus, instead of saving successfully but never being applied. Optimally, it should work correctly. :)


STEPS TO REPRODUCE
1. Switch to application dashboard, if not already enabled.
2. Open kmenueditor to edit the dashboard
3. Try adding new menu entries, separators and sub-menus
4. Click save
5. View (lack of) results in application dashboard

OBSERVED RESULT
No separators or sub-menus shown. Every entry is just dumped in to the first level menu.

EXPECTED RESULT
New menu entries should show up. Separators should show where they're added, and  sub-menus/folders/something should show for menu entries besides the top level menu.

SCREENSHOT
In the attached screenshot you can see the menu editor on the right hand side. It has test menu and test entry added to it at the top, both of which are not showing in the application dashboard on the left.

Also, the Games menu has been modified to include a sub-folder named 'Steam', surrounded by separators, with a number of entries (visible in menu editor). However, the sub-folder and separators are not shown in the application dashboard, and all of the entries are dumped together in to the main 'Games' menu.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora Workstation 33
(available in About System)
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Kernel Version: 5.9.16-200.fc33.x86_64