Assuming you are editing a child theme (or somehow protecting your changes from future update/over-writing) a very simple way to accomplish this is with a CSS rule that targets your mobile menu, then applies display: none to it.
Using a combination of media queries and carefully written CSS selectors, you can target exactly the HTML elements you wish to hide, and in what context.
My guess is you will need a combination of body class (for the correct content type), media query and appropriate CSS.