You cannot use the 'Install from zip file' feature with DAZ content simply because the compressed files contain a primary folder called Content where everything else is placed into. Your best bet is to either use a compression program to open the file and extract everything from within the Content folder or use DAZ Install Manager (DIM) to do the installation. DIM will extract all folders and files from the Content folder to anywhere you like as long as you have your preferences set up correctly. "Add to Library" only applies to runtime folders.