Selection of 2 attributes in variable product with more than 22 variations

Hi guys!
I have a new and important question.
I will try to explain my best.
I have a variable product, a ring with 2 selectable attributes.
I have 18 variations for each attribute, but we do not want all combinations.
I only need each first attribute with 5 second attribute.

Ok, then, my problem is:
In the first testing product, I have created 22 variations. In front end, when I select the first attribute, it is shown only the possible combinations with it.
In the second testing product, I have created 32 variations. In front end, when I select the first attribute, it is shown all the possibilities to choose, even those there are no combination, so I get a message: Sorry, no products matched your selection. Please choose a different combination.

What I have to do in order to have the second kind of selection in case os products with a lot of combinations?

I show you products page in private.

Thanks a lot in advance!
Estefanía.