Vanity url auto generation

Hello, currently we are using Webcenter Sites 11gr1, 11.1.1.8.0, and we are trying to implement a feature that would allow the auto generation of the vanity URL once an asset is created. I'm aware that there is a built in feature that allows to accomplish this, based on patterns (Configuring Vanity URLs - 11g Release 1 (11.1.1.8.0)), but we need to auto generate the vanity URL based on the structure where it lives in:

Ex. I have an product asset under different categories:

- Product Category 1

-- Product Subcategory 1

--- Product 1

Having the before mentioned structure, the vanity URL should be something like http://host/ProductCategory1/ProductSubcategory1/Product1