So what u r saying is
first the menu looked like this

SORT
|
MANAGER

Here Enabling and Disabling of manager Menu can be done,
now u have updated the manager menu like this :

SORT
|
MANAGER --- SUBMENU1
--- SUBMENU2

here u will not be able to disable the MANAGER menu as u will not be able to add an Valid event for it. Since u have added the SUNBMENU's now , u can again create the ONUPDATE event for them, then try to put the same logic into them and disable both of the sub menus. Here in the MANAGER menu when u click on it no event will be generated. MANAGER menu will be now same as SORT menu where valid event handler's cant be added. hope this helps u .