I have a button in my Bottom Bar that is called "All Buttons List". When I click on it there are 35 icons and one in particular for "Adjust Brightness".

I'd like to use this "Adjust Brightness" icon for my "SYSTEM" tab instead, but when I click/hold "SYSTEM" tab then select the "General" tab I do not see this particular icon at all.

How can I have a this icon in the "All Buttons List" but not in the SYSTEM/General tab icon list (85 different icons)?

It is the original "System Preference" icon from Mac OSX so naturally I'd like to have it on my "System" tab instead of being an "Adjust Brightness" icon.

Any help much appreciated.