Complex Gateway Scenario

Hi All looking for better modeling solution for complex gateway scenario

Default value of BMI be greater than 0

https://cawemo.com/share/43443159-7c63-44d1-b6d8-3b798eb3bf84

Many Thanks in Advance

What are you looking for exaclty?
A way of replacing the complex gateway or a better example of how a complex gateway might work?