Update custom fields with ScriptRunner based on the group the reporter belongs to

[Kerli Suve]

I have "Countries" field that I want to fill based on the reporters group, either when work item is created or the value for reporter has changed and I have to do it with ScriptRunner due to the amount of tickets created and Jira Automation limits. The field must be editable later manually when needed. 

I created an event listener for that but I am struggling with making the script work.

I can fill the "Countries" field but right away when I add a condition to check reporters group, i get some errors. This seems such an easy script so I am sure, someone in here could make this work in seconds. 

In Jira Automation it is pretty straight forward: 

1. When field value changes for Reporter
2. IF
   1. Reporter is in group "ExampleGroupA"
   2. Edit "Countries" to "ExampleCountryA"
3. ELSE-IF 
   1. Reporter is in group "ExampleGroupB"
   2. Edit "Countries" to "ExampleCountryB"

... and so on.