I can't decide, both sounds right and return results on Google.
So is it "any product group" or "any product groups"?
Context: The context is that some product can has sub-product that are part of groups, some have products and some don't. So I will add a method to know "any_product_groups?", "has_product_groups?", "any_product_group?", ... I'm not sure.
Example: "Has this product any product group(s)?"