You can do this by :
1. overlaying /libs/cq/experience-fragments/content/v2/conversion node
2. create rendercondition node Render Conditions — Granite UI 1.0 documentation , you can go with Privilege or Feature. Feature will give you the more control over Privilege but you can choose based on your requirement.
As Arun suggests - it's involves overlaying the ootb AEM code.