I have an object A which has fields Country,State and Product Type. It is going to save the product types available in the state. Another object B which is going to save product details. When the user selects the country of B, I would like to show only the states corresponding to the country record in object A. Likewise When the user chooses State, only the product types corresponding to the Country & state combination should be shown. Also I would like to add validations to make sure always the product type available for the corresponding state and country is chosen.
Please suggest how to do this. I know we could use triggers, any other ways for doing it?