Help Topic Selectmenu/Dropdown Format

Could someone please help with changing the format of the Help Topic dropdown on the open.php page? By default, the list items show as:
parent / child
parent /child
etc.

I would like the top-level parent to show as an option group like:
parent
   child
   child
parent
   child
   child

I am using version 1.10 rc 3.

Thanks in advance!