As discussed in various thread (last one is
here), Super categories for Clipart Groups are finally done.
It works the very same way as of Font groups.
So, it can only be used as Group level, which means defining a group in "LIBRARY GROUPS => Define Cliparts Groups" and using the group in "Configure Products => Configure Cliparts".
I am still working and thinking about adding keyword search, but hopefully this part will help a bit.
Let me know!