Sorry Lon but we don't see a way to setup the system to handle this requirement. It's somehow, complicated and could not be handled by the extension (and I am afraid of no existing extensions can handle it)
Our work-around for this was the coupon code. We set up a coupon code for people with multiple registrants that only work on group registration. It's an extra step for people to remember, but at least it allows the second discount.
The following user(s) said Thank You: Tuan Pham Ngoc
