Resolution: Won't Fix
Our users have been assigned to new groups on the basis of a corporate restructuring. The group names have been used for sharing filters, dashboards and comments.
If I delete the old groups, then JIRA asks for a new group name so that shared comments can be changed to the new group. That's great!
Unfortunately, this does not apply shared filters and dashboards. The filters and dashboards are no longer shared for other users.
Therefore, we have stopped deleting the groups. However, new employees are not added to the old groups. This will end in chaos, because we do not know exactly whether groups are still needed or not. The system becomes increasingly cluttered.
It would be nice if the shares of filters and dashboards could be changed to a different group, if groups are deleted. So just as it is already done for comments.