How to hide a submenu item

I´d like to know how to create a submenu and hide an item or even the whole submenu. I believe this must be obvious for the more experienced Editor X users, but I am lost here.

The reason why I need this: I´m creating a portfolio item, that leads to the portfolio page. In this page, the user will select the project from an image gallery. However, when the user enters a project page, the item Portfolio in the dropdown menu is not highlited ( I understand that the project needs to be a submenu for the Portfolio main menu to be highlighted).

The thing is that I don´t want the project pages to appear as the submenu of Portfolio (as they will be many), rather, I´d like to only organize them that way.

I´ve tryed adding the projects as a submenus for the Portfolio item, and then searched for a way to hide them from the menu, but could not find that option (I was able to do it using the regular wix editor).

However, I think it is an important visual asset to guide the user´s interactions in my website.

Thank you in advance for you help.