Hide Nav Items from different pages

Site URL: https://www.dirtkitchensnacks.com/

Hello,

I'm using the theme Brine and looking to do A and B testing on my site. I have duplicated all the pages and I'm looking to hide A navigation pages from B navigation pages and vise versa. Currently I have all my pages moved over to no linked and created individual links for all the pages in my primary and secondary navigations. What's the best way to hide specific url nav items from each page? 

Any help greatly appreciated.

Website password is dksnacks

To hide an item on any page, add this code to page Settings > Advanced > Header

here is an example for our story item

<style>
  a.Header-nav-item[href="/our-story"] {
    display: none;
}
</style>