The Ribbon Tool Palette (yes, it's a Tool Palette), is part of your workspace settings.
If the desired Ribbon Tab(s) are not presently shown
To add Tabs to the Ribbon, try Right Clicking the empty space to the right of the displayed Tabs, and see which options are available from the Tabs flyout.
Otherwise, from the CUI Editor, select your workspace in the left pane, then hit the Customize button at the top of the right pane. Now, in the left pane, navigate to the desired Ribbon Tab, and Check the item. You should now see this item added to your available Ribbon Tabs in the right pane (Ribbon node expanded). Select the Done button when the Customize button was, save your CUI, and hit OK.
Once the workspace has been restored, you should now have the desired configuration.
HTH