Preheat oven to 350°F (175°C).
In a large mixing bowl, whisk together the softened light cream cheese, Greek yogurt, buffalo sauce, and garlic powder until the texture is smooth.
Fold the shredded chicken and 0.25 cup of the mozzarella cheese into the mixture.
Transfer the mixture into an 8x8 inch oven-safe baking dish and spread evenly.
Sprinkle the remaining 0.25 cup of mozzarella cheese over the top.
Bake for 20 minutes or until the dip is heated through and the cheese on top is melted and bubbly.
Remove from the oven and garnish with sliced green onions before serving.