I have a module for Products. It has a Product content type and also a ProductPromotion content type. I have made the Product content be the parent of the ProductPromotion. I have a custom Product widget. In the widget designer I have a selector to pick the desired product. I now want to add a second selector that'll let me pick a ProductPromotion. I have laid out the selectors however, I don't know how to limit the ProductPromotion selector to only display the items for the selected product/parent only. As it is, it is displaying all ProductPromotions.
Ps: I don't have to use child content necessarily. I can have the product promotions be standalone content and use the related data field to associate a product to its promotions. Either way would wold work as long as the second selection list can be limited to the promotions for the selected product in the designer.