Stir tomatoes with their juices, onion, garlic, chipotle, oregano, cumin and salt in a 4-quart slow cooker. Nestle chicken breasts into the sauce.
Cover and cook on high for 2 1/2 to 3 hours until the chicken reaches 165°F and pulls apart easily.
Lift chicken onto a plate and shred with two forks. Stir beans into the sauce, mashing about 1/4 cup of them against the side to thicken the juices.
Return shredded chicken to the cooker and cook covered on high for 10 minutes until beans are hot. Stir in lime juice.
Warm tortillas in a dry skillet over medium heat for 20 to 30 seconds per side.
Use a slotted spoon to divide chicken and beans among 8 tortillas and serve 2 per portion.