We have many business units in our company that use Aha. each business unit has there own set of products and initiatives. when I am creating a feature in my workspace the initiative drop down shows every initiative for the entire company. while this maybe useful for a fringe case we instruct our teams to only select initiatives in their own product or business unit and then use roll ups to align cross business unit initiatives.
Having an option to filter the drop down to only see the initiatives in my active workspace or inherited initiatives from parented workspace would make the list much easier to work with.