I was able to make the three levels of menu with your data without issue. What I did was setup the dynamic link for the categories table with no filtering. Next I setup the products as a sub menu of the categories. I specified to filter on the cid column, nested. Next I added the sub category sub menu to the products. I choose to filter on the pid, nested. This gives me a three level menu that lists all of the categories, then each product for that category, then each sub category for that product. In my testing I found that you had many categories but only the abrasives category has any products, and out of those products only abrasive belts had sub categories under them.
I'm including screen shots of what the interfaces look like for the contents of this menu so that you have a visual reference to go along with the description.
