Currently with automation for Jira you cannot use groups in the actions unless it is to send email to a specific group. 

With group pickers being used at the JSM level it would be nice to be able to say if this group is select add users to this group for JSM requests. 

At this time we have to use the API to do this which takes more time or a 3rd party tool like script runner, power scripts, or build this out in something like BetterCloud. It would be most useful to be able to natively do this with Automation for Jira.