To edit the shown icons (or the order/grouping of the icons) in the CadActive tab in Creo, right-clicking on the ribbon, and select "Customize the Ribbon"

You will see the "Customize Ribbon" tab selected on the left-hand menu. Then select "TOOLKIT Commands" from the dropdown.

Add your Command to where you want in the ribbon.

When finished, select Import/Export -> Save Auxilliary Ribbon File. Select the CadActive application.

This will generate a "toolkitribbon.ui" file inside of %localappdata%\CadActive\cadactive-creo\text

Rename this file to cadactive.rbn, and copy-paste it into the "ribbon" subdirectory