If I understand your question correctly, it sounds like you are trying to move rules from one branch to another branch. Designer Studio allows you to move rules between branches using the "Save As" > "Specialize by class or ruleset" button on the ruleform header. Unfortunately, there is no way to do this in bulk. The other downside is that Designer Studio does not perform conflict detection when moving rules between branches - it's not a true "merge". By the way, Pega 7.1.8 contains a number improvements to the Merge wizard - including the ability to merge multiple branches back to their base ruleset at once.