Quick Answer
Yogurt does not use the same grams-to-cups value as every other ingredient. Using a practical US cup reference, 245 grams of yogurt is about 1 cup.
That means 100 grams of yogurt is about 0.41 cups, while 200 grams is about 0.82 cups.
Yogurt is denser than water and milk, with one US cup weighing approximately 245 grams depending on thickness and fat content.