How do I add a condition for all all developers but the assignee to be able to complete a transition?
You will need 2 AND conditions. One to check user is in role o specific group and another to check that the user is not current user.
I have seen the first condition in JIRA but the "not current user" is not a condition I have seen in the popular plugins. Might be out there somewhere. Else you will have to code it or write a script for it. Not hard.
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