Setup Filter with Search & Discovery app

For full filter functionality, we need to use Shopify's built-in Search & Discovery app.

In your Shopify Admin, click Apps >, then search for search & discovery

Click on the app, which will open a new page. Continue by selecting Install to install the app.

Once installed, look to the left and select Filters

Here, the Shopify Search & Discovery app has essentially pre-configured commonly used filter options.

If you want to add other filters yourself, refer to

Shopify Help Center | Modifying search with Shopify Search & Discovery