prune

What is the gallery overview ?

Unfortunately, as far as I know, you can’t go up a level when displaying galleries.
That mean you can only display album name when you are displaying an album.
If you display a gallery, you can only access things inside this gallery.

As I may be wrong, the best you have to do is display the full content of $album, $gallery, $galleries… with a print_r() function.
You can add this in the nextgen-gallery/view/ files. Also, you will find all the usable variables in the header comment of every file.

Last thought, as one gallery can be in many albums, if you finaly can get the album name from inside the gallery, you will have a multi-valued answer.