The Custom menu option will open a new window where you can select existing filter types for the tab you are on.
The Available Filters Window displays all the current filter types available that are in use on the specific tab you are on when you chose the Custom menu option.
The Removed Filters Window displays all the current filter types available that have been removed.
The Apply Button will apply all changes to the filters immediately.
The Cancel Button will empty any removed filters and close the window.