Spray 4-quart slow cooker with cooking spray.
In small bowl, mix 2 tablespoons of the lemon juice, 3 teaspoons of the garlic, the cumin, 1 teaspoon of the salt, ¼ teaspoon of the turmeric and the cinnamon. Coat chicken in mixture; place in slow cooker with ½ cup of the broth. Cover; cook on Low heat setting 4 to 4 ½ hours (or High heat setting 2 ½ to 3 hours) or until chicken is very tender. Transfer chicken with slotted spoon to cutting board; shred and reserve. Discard cooking liquid.
Meanwhile, in 2-quart saucepan, heat oil over medium heat. Stir in rice and remaining ¼ teaspoon turmeric; cook 1 minute, stirring constantly. Add remaining 1 ¾ cups broth; heat to simmering. Cover; reduce heat, and simmer 18 to 20 minutes or until liquid is absorbed. Let stand 5 minutes covered; fluff with fork.
In small bowl, mix yogurt, remaining 1 tablespoon lemon juice, remaining ½ teaspoon garlic and remaining ½ teaspoon salt. Divide rice among serving bowls; top with chicken, tomatoes, cucumber, red onion, fresh herbs and pita. Serve with yogurt sauce.
