You can stack up to three controls — buttons, split buttons, and galleries — in a button group. For an example of a button group on the Ribbon, see the Hostgroup on the Sessionribbon: Connect, Disconnect, and Quick Keysare combined in a single button group.
To add a button group
Open the UI Designer.
From the Design View pane, from the Ribbon simulation, select the tab and group to which you want to add the control.
To select a group, click the group name. Create a new group, if needed.
From the Insert Controlspane, click Button Group.
From the Subitems Collection Editor dialog box, click Add and then select the item you want.
Repeat the previous step to add additional buttons, split buttons, or galleries (up to three items total).
With a button, split button, or gallery selected in the list, set the action and other properties.
When you have finished adding and configuring items to the group, click OK to close the Subitems Collection Editordialog box.
Click OK.