XnView Software

I know that you can filter pictures by category by selecting the ones you want in the Category Filter; however, this is sometimes buggy and doesn't allow for much customization. What I'm proposing is a full fledged, text-based category filter, where you can type the name of the categories you want ...

Basically what the title says; say I have a tag tree that looks something like this
-Family
----Siblings
--------Brothers
--------Sisters
----Parents
--------Mom
--------Dad

If you tag a picture as, say, "brothers", it is only tagged as "brothers", and not as "brothers", "siblings" and "family ...