Hi again @keeboudi !
The short answer is: no. By design, the navigation menu that Better Section Navigation displays is based directly on parent/child relationships between Pages and/or other hierarchical post types.
Longer answer: you could work around this restriction using dummy pages and redirects. For example, if you wanted a nav with a parent page called “About Us” and links below it for “Our Team” (another page on your site) and “Our Sister Company” (a link to another site), like this…
+ About Us
|– Our Team
|– Our Sister Company
…you could create an empty page titled “Our Sister Company”, set its parent page to “About Us”, and then use a plugin like Redirection ( https://www.ads-software.com/plugins/redirection/ ) to point the URL for the “Our Sister Company” page to the sister company’s site, so that when someone clicked the link to visit the “Our Sister Company” page on your site, they would be redirected to the other site instead.
Depending on your situation, it may be simpler to use a true menu instead of Better Section Nav, since WP menus support custom links out of the box.