Quite a few!
These days nearly any dog can be a working dog, but if you're thinking of traditional working dogs in their traditional roles, the answer is very much, "YES!"
Komondorok are bred here in the U.S. mostly as pets, but plenty of them work, particularly in the midwest and west where there are still flocks of sheep and herds of cattle to guard. There aren't many around as the coat is time consuming and they are still very much guard dogs. Whether they guard your family or your flock, Komondorok always work in their minds.
Here in the northeast many people keep hounds and retrievers for hunting as well as house pets. They do well either way.
Around the world the situation is quite different. In many places outside of the developed world, dogs earn their keep just as they always have. The Laikas of Russia are a great example. Few people keep them here as they make poor house pets, but in Russia they're still used for bear and other game hunting. Salukis still course hares, and herders still herd, even here in the US. There are many, many, breeds of dog we do not hear of here in the US simply because they are still working dogs for their local populations, earning neither fame nor adoration because they either make poor pets or never made the news.
Take a look at the
Perro de Pastor Mallorquin. The breed has been around for ages yet it's just another working dog for the people who live in the Balearics. There are hundreds or maybe thousands of breeds like this all over the world, humbly working in anonymity.
There are terriers that still dig too. Go up that list a bit and look at the
Patterdale Terrier. It's now a very popular breed in the UK amongst farmers and vermin hunters. The job may not sound important until you lose a steer, horse, or sheep to a leg broken by stepping in a varmint hole.
Here in the US we tend to neglect the usefulness of dogs in their traditional roles. That wasn't always so. Many farmers would have several dogs, each for a purpose. They may have had a herd guardian, a herd shepherd, a terrier, and maybe even a hunting hound. All of them help people in rural areas with their agrarian lifestyles. Here we have agrobusiness instead though many small family farms still keep dogs for exactly the reason they were bred just as their counterparts do all over the world.