To create a group of tool buttons, select the buttons you want to associate and set their Style property to tbsCheck; then set their Grouped property to True. Selecting a grouped tool button causes other buttons in the group to pop up, which is helpful to represent a set of mutually exclusive choices. 

Any unbroken sequence of adjacent tool buttons with Style set to tbsCheck and Grouped set to True forms a single group. To break up a group of tool buttons, separate the buttons with any of the following:

• A tool button whose Grouped property is False.
• A tool button whose Style property is not set to tbsCheck. To create spaces or dividers on the toolbar, add a tool button whose Style is tbsSeparator or tbsDivider.
• Another control besides a tool button.