Registration on Leve 0 and Leve 1

Hello.
I made categories restrict with Level 0 and 1. Level 0 user can see the allowed categoris without payment. In order to access Level 1 categories, users have to pay.
However, Level 0 registration form shows as same as Leve 1. It ask to pay for Level 0 users. They use same registration page.
How do I make it difference?
Thanks for awesome plugin.

https://wordpress.org/plugins/s2member/