Instead of having 30+ items in the drop down which is separated by different categories, is it possible to use RadMenu inside Combobox to display something like this. When the user hovers over Section A (which is a separator), it automatically displays the child menu for section A to be selected. I saw some references to TreeView but using menu is probably simpler? They key is auto expand/collapse that the menu inherently supports.
Section A ---- Item A1
---- Item A2
Section B
Section C
Section D
Section A ---- Item A1
---- Item A2
Section B
Section C
Section D