Suggestion for the keyword hierarchy

It seems to me that a lot of folk would like to have extra labels for stuff like ‘POV’ and ‘appears in scene’ which I think is a great idea, but I’m not really sure why the keywords can’t be used for that. I use a hierarchy, so under ‘POV’, I have a list of characters, and then under ‘Appears in scene’ I have the list of characters (again).

So when assigning keywords, I thought it would be nice if I typed a top level keyword, Scriv would allow me to pick from its children and separate them in the list with a colon or something. Likewise, if I go on to type a keyword after the colon which isn’t part of the POV keywords for example, then Scriv could enter into the keyword HUD under the correct keyword.

Perhaps something similar for the search, which would fill type:value keyword for filtering out documents.