Hiding a page from navigation menu

Hi,
on some previous version of WP it was possible to specify a page attribute to hide it from the main navigation menu. As I rarely update my homepage, now I cannot find that anymore.

https://www.sculptartes.com

On the left there’s an item “Stein, Holz” preceded by a solid bullet. Beneath there’s an item “Ans Licht” preceded by a hollow bullet. This item should not be be visible here.
How do I do that??

Thanks for hints,
Steinspecht