How do you change what choices are shown based on the choices made in another variable in a record producer?

I'm creating a record producer where a category and subcategory is shown.

Subcategory and category are both custom variables that are drop down lists. But I want the subcategories to be based off what category is shown.

For example when someone chooses phone for the category I'd like the subcategory to show phone related items.

Would this be a good place to use variable sets?