The night before, soak the beans in water, you can do this in your slow cooker, add enough water to cover, plus a few inches. Let this soak overnight, don't turn on slow cooker yet.
In the morning, drain the water off the beans, add the chicken breasts, 3 1/2 cups of water, onion, garlic, chile powder, cumin, oregano,(add salt when done)
Stir.
Set the slow cooker to Low for 9 hours. DO NOT OPEN THE LID!
After cooking time is done, shred the chicken, you can do this right in the slow cooker with 2 forks.