Generally a hidden collection won't be accessible in Liquid, but it is when referenced via a menu (linklist). It's important that your code can handle this possibility and skips the hidden collection in your loop - let's look at the simple code to do it.

grabbing the liquid snippet...

There's no real magic to this. All the code does is loop over the menu like you'd be doing now, but is checking the published date. A collection with a date is visible on the online storefront channel. One without is hidden.

That should be enough for you to adapt to your needs. See the related folder in Shopify Code Snippets repo.