Context filter "Has taxonomy term ID (with depth)" when taxonomy term belongs to product and not product display
I have a view to show my shop products in a categorized way.
I have noticed that if the taxonomy term field is at product display, i can add the filter context "Content: Has taxonomy term ID (with depth)" but if the taxonomy term field is at Commerce Product i cant see that (even when having the commerce product as a relation in the view).
If the relation is in place, i should see some context filter called "(Product) Commerce Product: Has taxonomy term ID (with depth)" but it doesnt.
I need this because in a given taxonomy term i should show the products directly in this term and in any child term.
I cant change the taxonomy term from commerce product to product display because the products are sincronized from openerp and the products category are managed there (in the openerp system) and not at the product display level.
Anyone has any idea about how to solve that problem?