Show folders in navigation, modular subpages not

Hello,
I'd like to have this navigation menu (without modular onepage skeleton subpages):
01.modular-home (modular)
03.standard-page-3

02-standard-page-2 and the subpages of the 01.home skeleton should not be outputed in the navigation menu.

I'm using the onepage skelton from the big-picture theme
Can anyone help?

Are you using the Antimatter theme? You could try adding the following to the 01.home page (assuming this page uses modular content) frontmatter:

onpage_menu: false

I'm using the big-picture one-page skeleton

I have inserted it but can't get it to work with the frontmatter code. I ve set it on top of the modular.de.md file in the 01.home folder but it doesn't take any effect.

I also read https://github.com/getgrav/grav-plugin-admin/issues/72

I would just like to reduce the amounts of entries in the navigation menu because big-picture theme doesn't have the responsive design "hamburger", so the entries overflow (even faster on little screens of course).

At the moment I use #nav {display:none;}

I've contacted the contributer of the theme.
https://github.com/tranduyhung/grav-skeleton-big-picture/issues/3

You have to change this in template file header.html.twig