How to map one album in Photos? In Photos, I can press the 'Places' button and see a map with all my photos.
How do I get the map to show the photos of only one album?
In Photos for Mac OS:

Visit the album you'd like a Places map for.
Click Show as memory at the top of the main window (located directly under the name of the album).
Scroll down, and you'll see a Places map with only the photos of the active album.