By default only a JIRA administrator is able to assign users to groups. If you want other JIRA users (e.g., project administrators) also to assign users to groups, you have to give them JIRA administration permissions, but this can cause other security problems.
The approach of catWorkX Extended Group Management is to transfer group management to a group management project in JIRA. Each group is represented as a JIRA issue within this project. With the condition, validator and post-functions included in catWorkX Extended Group Management, you can synchronize these group issues with the real JIRA groups.
Project managers can manage the group assignments by executing the provided workflow transitions while only JIRA administrators are able to manage group assignments directly.
At the moment, you can obtain the catWorkX Extended Group Management add-on as JAR file only directly from catWorkX.