Using script runner plugin it's pretty straightforward.
issueFunction in parentsOf("assignee = currentUser()")
While running your given scrip I get following
Could you please tell me how to get this access? What should Admin do and where to give me such access?
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.