Place beans in a colander (if using Hurst's beans, remove the seasoning packet and set that aside), rinse the beans, remove any debris or bad beans, then add to a container and cover with 2 inches of water. Set aside to soak for at least 6 hours.
Drain and rinse the beans after 6 hours, place in your slow cooker, add 2 quarts (8 cups) of water, and 2 tablespoons of oil. Place the lid on the cooker and lock in place. Add the weight on top and place on high heat. When the weight (jiggler) starts to move and vent pressure, turn heat to low or medium low to keep the weight moving and venting. Set your timer for 9 minutes.When 9 minutes have passed, turn off the heat and move the pressure cooker to an unused burner and allow to release pressure naturally (about 15-20 minutes) until you have indication of zero pressure inside the cooker. While waiting for the pressure to release, continue with the next step. Add the chicken breasts, celery, carrot, onion, garlic, and seasonings to the slow cooker. (If using the bag of Hurst's beans, add rosemary, and if using the homemade bag of beans, add the Italian seasoning, oregano, and basil.)
When you have zero pressure in the slow cooker, remove the lid, drain the beans, and add the beans to the slow cooker.
Pour in the chicken broth, give the pot a stir, place the lid on, and set to the High setting for 3 hours.
At the 3 hour mark, remove the rosemary sprig if you used fresh. Remove the chicken to a cutting board and cube and return to the pot. Add the diced tomatoes, and if using the Hurst's beans, sprinkle in the seasoning packet from the beans. Give the pot a stir, cover, and continue cooking for another 30 minutes to an hour.
Taste, season with salt and pepper as desired. Serve and enjoy.