Rod of Underworld Navigation

This finely carved rod is decorated with gold and small dragon scales. While underground and holding this rod, you know how deep below the surface you are. You also know the direction to the nearest exit leading upward. As an action while underground and holding this rod, you can use the find the path spell to find the shortest, most direct physical route to a location you are familiar with on the surface. Once used, the find the path property can't be used again until 3 days have passed.