Tap the filter button.
Tap the info button for the filter you want to edit.
Tap the Included Stores row to modify which stores are included in the filter.
Tap on store(s) to include or exlude them from the filter. You can also select whether or not items that are not assigned to a store are included in the filter.
When the filter is configured to your liking, tap the Done button.
Note: AnyList Complete is required in order to filter lists.