You can create a group of mutually exclusive Toggle Buttons with the ToggleGroupName property.

Complete the following steps:

1. Select the Ribbon Group to which you would like to add a group of toggle buttons. This will enable the group's floating toolbar.
2. Click the Actions drop-down button. This reveales the Ribbon items available to add to the group.
3. Select Add Toggle Button from the list. A labeled toggle button will appear on your Ribbon control.
4. Select the toggle button to activate the button's floating toolbar.
5. Click the Miscellaneous Settings button to open the Miscellaneous dialog box.
6. Enter Edit for the ToggleGroupName property as in the following image:
   
7. Continue to build the group by adding more toggle buttons and setting their ToggleGroupName property to Edit.