In Customer Portal Settings (More > Customer Portal) one of the tabs focuses on the Product Filter Menu, which can be configured to display in the customer portal.

It can help streamline your customers' shopping experience by allowing them to narrow their search if they ever wished to add more products to their subscriptions.

To make it function properly, you will first need to navigate to your Products section in your Shopify Admin. Select a product(s) you are interested in creating a filter out of, and scroll down to view the Product organization section, as shown below.

Choose from any of the organization fields and copy its contents to use with the product filter menu.

As an example, we will use Tags. For this product, we will use the tag Wheels and Covers.

And for a second example, for this hat product listing, the tag to use is Hats.

Now come back to the Product Filter Menu section in Appstle, and click to enable the product filter. In our case, we will create the filter based on Tags.

Click Add Filter to bring up a pop up. Give the filter a title, enter a label, paste your products' tags into the value field, then hit Add.

Repeat this process for any other product tags you want to use.

Hit Save in the upper-right when you are finished.

Now login to your store with an account. If you have not already, conduct a test purchase for a subscription product to ensure that you can access the customer portal.

Scroll down until you see a section for adding products. Click the filter icon on the far right to bring up the Categories field. You can click on it to reveal all of the filters you set in your customer portal settings.

Click on a filter to reveal all of your products corresponding to it.

Tires (showing products with the 'Wheels and Covers' product tag)

Hats