FILTER_VHOST should filter on site domains and inherit mail domains that are members of those

At the moment it seems FILTER_VHOST basically looks at the domain you used to access the web interface and then only shows mailing lists where that domain is part of the mail domain of the mailing list.

You'd get more flexibility if instead it took the domain you accessed the web interface, checked to see what site domains match that, then only show mailing lists that are members of mail domains that are members of that site.

:)