Seo Long Tail Url On Filters?

Hi all,

I am wondering if it is at all possible to get some Long Tail URL's on the product filters. At the moment I feel like we are missing crucial SEO as we have no longtail deep links showing for many of our products when we have many different options available to our customers but yet Google just doesn't see it, although we do have canonical links which are indexed online ideally I would like to see;