Combine refried beans with taco seasoning and mix well. Add 1-2 TB of water, as desired to combine bean mixture until smooth.
Remove avocados from the skin and mash with lime juice to reach desired texture.
To assemble: Add 2-3 TB of the bean mixture to the bottom of each cup. Spread into an even layer using the back of a spoon. Add a spoonful of the corn, then avocado. Follow with a layer of a spoonful of Greek yogurt (or sour cream), then a spoonful of salsa if using desired. Sprinkle with a layer of cheese, then finish by layering tomatoes, olives, cilantro and green onions. Store in refrigerator and serve with tortilla chips.