Because your Sermons exists through their own permalink/slug, using external URLs will be your friend. Unless you've already added a custom domain to your Sermons page, your Sermons automatically live at your Nucleus domain, with the permalink /media.
NOTE I: For more information on how to add a custom domain, or subdomain, to your Sermons, click here.
NOTE II: The following instructions will utilize knowledge of how to build cards and add links to your navigation menu. For more information on how to add a card to your Nucleus, click here. For more information on how to add a link to your navigation menu, click here.