I want to see a map with all the places in one album, is it possible??

No, it is not possible by album. You would have to hide all photos that are not in the album, to see only selected photos from an album on the Places Map: Find photos by location in Photos on Mac – Apple Support (UK)

It would be easier to export just the photos from this album and import them to a new, empty Photos Library. Then you can see them as thumbnails on the Places map in the new Photos Library.

See: Create additional photo libraries in Photos on Mac – Apple Support (UK)

When I click on an album, not selecting any pictures, and open the Info window with command-i, I see a map with pins in all the location of the pictures in that album. Is that what you want?

You're welcome, Johannes 😊