Hi Matt,

On this related list on RITM form, you can right click on the header and navigate to configure-> list control

On that form there is a check box called 'Hirerchial list', check that and it will allow you a drill down on the list form here itself., i feel this is the best solution for you.

Be sure that on the catalog task you have the related list added already. (To get that, right click on the header of catalog task form and configure -> related list. Add the catalog task-> parent related list as the first on on that form)

-Anurag