where is the sub-level area

If you want to create multi-level drop-down options then this is possible with our Dynamic Dropdown Widget:

http://widgets.jotform.com/widget/dynamic_dropdowns.

You can add this widget to your form by following this guide: http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form

Let us know if you have any further questions.

Thanks