Hi Daniele,
Actually, yes. It is not an officially supported or documented feature, but it should work with taxonomy and custom field drop-down (or radio button) filters.
You can use the same syntax, with the taxonomy or custom field name, like {taxonomy_name} or {custom_field_name}
In case of categories/taxonomies it will replace it with the taxonomy term ID, in case of custom fields it will use the custom field value.