The JIRA Toolkit plugin has a custom field for this purpose. If you're attempting to get this data in field form this is likely your only non-custom option. JIRA Toolkit available for free for JIRA Server and JIRA Cloud.
The custom field is of type Participants Field.
It's my belief that this only includes Assignee, Reporter, and Commentors though, so I am not sure if users triggering the Issue Update event will be added to this. Good luck.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
We're bringing product updates and pro tips on teamwork to ten cities around the world.Save your spot