I am creating a model tool which is 95% complete but I want the tool to be able to select a category from the value list of categories and only all the classes that belong to that category shows to which one can select from. For instance of we have a group like this; Continent: Africa, Europe, Asia . Country: Nigeria, Ghana,Kenya, Egypt, Germany,Italy, Albania, Japan, China, Indonesia. By selecting Africa in that continent category, automatically gives you only options of country that belongs to that continent.
Please I really need an urgent answer for me to know if it is possible and how?. Thanks