This is one part of my menu and I want to show a menu when I go to portfolio or any page under portfolio. I know I can take their ID and use is_page and get what I want. But the problem is in the future if I add another page it's gonna mess it up. Because I'll have to add that pages ID into my code. I don't want to do it actually my customer doesn't know how to do it. I thought about using !is_page then adding other pages so any other created page will have this menu but what`s gonna happen if they add another page to their website that is not under portfolio ?
Long story short is there any chance I can say is_page portfolio or child of portfolio show this menu ?