okay @Jeff_Bomar
my rapid feedback goes as follows
you have products and sub products in my table related via a lookup. In the example sub products should start with the same number, thus in the example below you can still select too many sub products
To limit the selection we apply a filter in the lookup, that is not as self evident as I would like it to be, but in this example I used:
More about this kind of filtering here:
hope it helps, cheers, christiaan
and here the link to the doc: example