I want to hide the SubCategory and Item drop downs in the new incident form if they are empty. My issue is that when a Category is selected an on category change field rule doesn't show the Subcategory field as it isn't updated with the new values until the drop down is selected in the form. How can I refresh the list in subcategory and item fields on the field rule so that it realizes that they are no longer empty and to display the fields in the form?