I currently have two combo boxes. In one, the end client will select a category. Based on this category, the second combo box should display a specific list of other categories which should then drive a filter variable. Currently, I have to create the first combo box, then create, using R, an output that takes the categories from a variable, table, or as a direct-input list, and then returns the options/categories I want to show in the second combo box. Finally, reference that output in the second combo box. I would like for this to be possible without code and made easier, with fewer steps.