Defining a Menu in the Toolbar 
Just as a context menu, a menu of the toolbar is an instance of class CL_CTMENU. You can freely define several menus and add them to the toolbar.
Define a GUI element of type 1 (menu with a default button) or type 2 (menu without a default button) in the toolbar. For a description of the procedure, see Defining GUI Elements in the Toolbar.
More information: Special Aspects for Menus with a Default Button.
In the event handler method of event MENU_BUTTON, query the function code you assigned for the menu in step 1 (using event parameter E_UCOMM). This way, you can distinguish between the different toolbar menus.
For each function code, define a menu as described in Defining a Context Menu.
For each menu function, assign additional function codes in step 3 that you can query in event user_command.
Note
See also report BCALV_GRID_07 in development class SLIS.