How to ignore a folder merge from one stream to another

Our SCM team want to restrict couple of folders in a component to merge from one stream to another stream. The team created a jazzignore file in both source and target streams adding the folder names to ignore and tested that the files changes or adding new folders in those ignored folders are not updated in unresolved changes. But when a merge is performed between the streams, all the changes including the ignored folder changes are getting merged. Please let us know how to address the request from SCM team.

RTC version :6.0.6.1

Thanks,

Vinay