Iris theme supports advanced product filtering which requires the official Shopify Search and Discovery App to be installed. Once you install the app make sure to get familiar with it as it offers quite a few nifty features you can use in your store.

Once you installed the app head on to “Apps” in your Shopify admin and select “Search and Discovery”. From the “Features” select “Customize Filters” option and click “Add Filter”. Now click the search field and you’ll be presented with a list of filters currently applicable to your products that you can add to your filter.

One cool thing you can do is filter your products by metafields. This enables you to create search filters even better dialed in for filtering specific properties of your products.

For example you can create a metafiled named “Skin” and then have a filter that could filter by various skin types i.e. dry skin, oily skin, mixed, etc.

To set up that option you go to “Settings->Custom data”, click “Products” and then “Add definition”. You can name your metafiled “Skin” and then in “Select Type” select the “Single Line text” and save.

Now you go to Products in your Shopify admin and for each product you want to include in that filter you add  a skin type in the “Skin” metafiled at the bottom of the product editor.

In the end you go back to the “Search and Discovery” app and add the “Skin” filter.