You have two options.
Create the Zone One and Zone Two top level categories and create duplicate categories under each Zone. The if you’re using a premium template that has a category drop down you could use the enable_category_by_root_parent shortcode option.
The other option would be create your two zone categories and all the other categories and then use the category_in. Doing it this way, you would have to create a page for each category in each zone.
Personally, I’d op for the former because it would involves a lot less work.
Hope that helps.