Liquid Collection Navigation
From Spiffy Stores Knowledge Base
A product is an independent entity and may belong to many different collections.
Since a collection is just a list of products, when you view a collection and then view a product from within that collection, the product is displayed, but there are no indications as to the collection from which the product was selected.
Many web designers wish to create a way of navigating within a collection.
This tutorial explains how to add this feature to a theme which doesn't already support it.
A product is always referred to by a URL such as
/products/blue-tshirt
A collection is always referred to by a URL such as
/collections/sale
What we need to do is to tell the software about the collection we are currently using while viewing at a product. We can achieve this by using the new nested URL scheme
/collections/sale/products/blue-tshirt