Hash Sets - Ignore Known Files?

I have two hash sets - the NSRL “known” and another listed as notable. There are several hundred which are both.

The file filter appears only to list “or”'s such as “known ‘or’ notable” but not “notable ‘but not’ known”.

Can I make a hash-set ignore known NSRL files?

Can I filter for notable but unknown files?

Or, is this a Python module I need to develop?

Thanks!