Here
I'm not working with catver.ini, because catver.ini is not necessary for filters.
Just use and edit your romlist manually.
As an example to my OpenBOR display (in my case : C:\attract\romlists\OpenBOR.txt ), i want to filter games by category 'test'.
#Name;Title;Emulator;CloneOf;Year;Manufacturer;Category;Players;Rotation;Control;Status;DisplayCount;DisplayType;AltRomname;AltTitle;Extra;Buttons
GoldenAxeLegends;GoldenAxeLegends;OpenBOR;;;;test;;;;;;;;;;
GoldenAxeMyth;GoldenAxeMyth;OpenBOR;;;;;;;;;;;;;;
HE-MAN;HE-MAN;OpenBOR;;;;test;;;;;;;;;;
Night Slashers X;Night Slashers X;OpenBOR;;;;;;;;;;;;;;
Start AM > press TAB key > Controls > Set a button for 'Next Filter'
Start AM > press TAB key > Displays > choose your emulator display (in my case : OpenBOR ) > Add Filter >
name your filter (in my case : display_all_test_games ) > Target : Category > Comparison : eqals > Filter Value : test
Goto romlist (where you can starts the games) > press your definied 'Next Filter' button. AM shows the 'Favourite Games'-standard filter. If you don't have set a game as a favourite, you will see an empty romlist. If you have chosen/set a game as favorite, you will see your favorites.
If you press 'Next Filter' again, you get to next filter.
In my case : display_all_test_games (GoldenAxeLegends and HE-MAN)