Libraries on device

I have had digital editions installed on my laptop for years, and have been able to easily create "sub libraries" for want of a better description, in order to be able to find particular genres easily and not have many hundreds of books to search through.

I have recently purchased a new tablet (Samsung) and have installed digital editions on it, but the library functionality appears to be limited and I can't figure out how to create sub folders in my library.  Does anyone have any hints?  Or does this functionality not exist when installed on tablets?