For example: set up Buy one get the second 20% off, get the third 30% off with bundle:
https://treedify.com/selly/bundles
In bundle offer setting, it needs 3 product groups:
Add/remove product groups to create big bundle
Set bundle discount option "Various discounts":
Set different discounts in different groups:
Group 1 with no discount:
Group 2 with 20% discount:
Group 3 with 30% discount:
