Use is_user_logged_in() to show link only or logged in users.
And use the_author_meta() to get url to google drive.
Like this inside The Loop:
<?php if(is_user_logged_in()): ?>
<a href="https://wordpress.stackexchange.com/questions/201838/<?php the_author_meta("google_drive_url') ?>">Click to open Google Drive</a>
<?php endif; ?>