Groups in (custom) list filters

Hello, I have scoured the handbook and the forum already, as I had the impression of having seen this question before. Problem is that “filter” means at least three different things (transformation filter, list/smart filter, metrics/hinting filters…).

Anyway, what I’m trying to do: I have a custom filter plist with my personal character sets. In these list filters, I would like to add categories as they normally also appear in Font View: Letter, Number, Punctuation…

Is this possible? Thanks!

Thank you. Maybe I wasn’t clear:

I want to add categories within my custom list filters. Like this:

Can I add these within a list filter?

This is not possible as far as I know. You can add custom headings in the glyphOder custom parameter like described here: