Preheat oven to Hi-Broil. Place chilies on a foil-lined baking sheet and broil until skin is blackened, 10-12 minutes, checking often. Wrap foil around chilies and let sit 10 minutes. Scrape off loose skin and discard most of the seeds. Chop finely.
Mix together chicken, corn, sour cream, oregano and salt.
Place a Reynolds Slow Cooker Liner inside a 5-6 1/2 quart slow cooker bowl as directed on package. Using half of each ingredient, layer beans, scallions, sour cream mixture, jalapenos, salsa, tomatoes and cheese. Repeat, ending with cheese. Cover slow cooker and cook on Low for 3-3 1/2 hours. Use Warm setting to serve. Serve with tortilla chips and sliced raw vegetables for dipping.