Unsubscribe has been moved from Store Setup to Templates and Batch Setup. The Unsubscribe Text and the Unsubscribe Url are visible for each store and branch, the Unsubscribe Url is not customizable however the Unsubscribe Text is customizable per Store/Branch. To grant access for a user to view this tab in Templates and Batch Setup would be done in User Setup - User Access.
*By default all Admin Users will have access to this tab.