Sometimes you want different people from the same group or role to execute different steps of the workflow. For example, the person thatresolvedan issue should not be the same person thatvalidatesthe fix.
You can put the following code as a condition on theValidateaction, which will prevent the same user that did theResolveaction from validation:
def changeHistoryManager = ComponentAccessor.getChangeHistoryManager()
def currentUserKey = ComponentAccessor.getJiraAuthenticationContext().getUser()?.key
// returns true if there are no transitions to the target state by the current user
it.field == "status" &&
currentUserKey == it.userKey &&
"Resolved" in it.toValues.values()