When you would like to bulk select multiple assets from multiple albums, this is possible using my selections.
While bulk selecting assets from a location, click the 'Remember Selection' icon:
You can navigate through other albums/locations within your library and remember selection.
The selections will all be available within the My Selections album:
Within here, you can bulk select your assets to perform actions.
You selections will clear out automatically upon logout.
To remove assets from my selections, select the files and click remove.