Hi,
You can click on "Add filter" to add a second filter. This is a filter of the type AND, meaning the user have to match both criteria.
Set the first filter for Subscribed to list A and set the second filter for Unscubscribed from list B and you're good to go.
You also can create a second filter by clicking on OR. That would result in a segment. for which the subscribers has to match at least one filter.
Segments are documented here: https://docs.acymailing.com/main-pages/segment
