Smart Category Menu does not highlight my category

How Volume's Smart Category Menu decides which parent menu item to highlight, and why it needs a metafield to work.

Smart Category Menu keeps the top-level menu item of the section a visitor is browsing marked as active — so a customer deep inside a product page still sees which part of the store they are in.

It needs two things: the checkbox enabled, and a metafield telling the theme which top-level item each page belongs to.

1

Turn on Smart Category Menu

In Customize, open the Header section. Under the Menu heading, pick your top-level menu in Menu, then tick Smart Category Menu.

The checkbox stays hidden until a menu is selected in Menu — if you cannot find it, that field is still empty.

The Menu drawer section has its own Smart Category Menu checkbox in the same place. Mobile does not inherit the header setting, so tick it there too.

2

Create the metafield

Go to Settings → Metafields and metaobjects → Collections and add a definition with the namespace and key custom.top_level_category, type Single line text. Repeat for Products if you want product pages to highlight too.

3

Fill it with the menu link's handle

This is the step that usually goes wrong. The value must be the handle of the top-level menu link, not its visible title.

A menu item shown as New Arrivals has the handle new-arrivals — so the metafield has to read new-arrivals, with a hyphen where the space is. Capitalisation is ignored, New-Arrivals matches just as well, but New Arrivals never will.

Products fall back to their tags when custom.top_level_category is empty, and the same rule applies — the tag has to be the handle form of the menu link. A tag reading New Arrivals does not match the link new-arrivals.

The highlight only appears on the plain collection or product URL. Filtered, sorted and paginated URLs, and search results, are not part of the match.

If Breadcrumbs is enabled in theme settings, product pages are matched against the collection-scoped URL (/collections/…/products/…) instead, so the highlight follows the collection the visitor came through.

The same Menu group holds Highlight menu items — a text field where you list menu item names separated by commas. That one is a styling accent on specific links and has nothing to do with Smart Category Menu; the two are easy to mix up.

Full setup in Smart Category Menu.