Can you narrow down records in a portal using conditional value lists

[mpau]

I have a database I developed a ways back with tables ORDERS, LINEITEM, PRODUCT, and PRODUCTGROUP. Each Product belongs to a Product Group. Groups are essentially master products and the products are style variants of the master product or product group they belong to. So for example, master product Chair and product is Chair Red (style), Oak (material). The reason for breaking the products down this way is because of a draw on an inventory parts list that is different for each product variant.

Till now everything has worked beautifully. I create LINEITEM records via a portal on the order page and currently have it working via a relationship between _kProduct(Product) and _fkProduct(Lineitem). I select the products from a dropdown list populated by product names. But recently, the list of Products has gotten so long that the drop-down Product Value list is getting too long. So, I'd like to narrow down the list for the users starting with ProductGroup (only 12 compared to the 60+ list of Products). Ideally, I'd like the user to be able to make selections in the portal starting with Product Group and then moving through Style and Material (populated by conditional value lists sorted by Product or Product Group).

My question is: is it possible to set up a portal where the user is able to select products based on criteria like product group, style and material rather than having to select the end product itself? Can filemaker find the appropriate end product?