This is a very special problem I met in Prestashop. I have a product, let's say a two color wooden stick, which is a normal 10" long stick. Half of it (5") can be blue and the other half red for example.
My product is this: Two color wooden stick. I have the following features: color 1 and and color 2 .
In the admin at the product's features I check red for the color 1 and blue for color 2.
Now the problem: when user filters using layered navigation, maybe they select blue for color 1 and red for color 2. This will result displaying 0 products as our wooden stick is inverse, but in the reality it's the same product.
How could I make that possible without duplicating the wooden stick product?