Do you have multiple landers and/or multiple offers that you want to specifically assign?
If you have 2 landers and 4 offers. You want this flow:
Lander 1 -> Offer 1 and Offer 2
Lander 2 -> Offer 3 and offer 4
Here's how you do it:
NOTE: If you are using Machine Learning, the weighted traffic split % will be over-rided by Machine Learning.