In HERE Drive or HERE Drive+, swipe up from the bottom of the screen, and tap Settings > Navigation licence.
With Lumia Black phone sw (and earlier), you have either HERE Drive or HERE Drive+ in your phone. HERE Drive+ provides global navigation license while in HERE Drive the navigation only works in your home country or area. You can expand the service to all countries and areas where navigation is available. To do this, swipe up from the bottom of the screen, and tap Settings > Navigation licence > upgrade now.
With Lumia Cyan phone sw, the global navigation license is available for all Lumia phones after installing the latest HERE Drive+ from Store (v4.1 or later).