Sharing the albums is not supported for the Shared iCloud Photos Library. We can only share the media (photos, videos). It is confusing, that we are still seeing the shared photos in their albums, but not the other subscribers to the shared library.
On my Mac I am using this work-around to keep the album organization. I am tagging the photos with the name of the album as a keyword. Then I can easily the recreate the albums as smart albums in the shared library. On your iPad you may want to add the name of the album to the caption - but the caption would have to start with the name of the album, or the search may not find it.