Bring 1 1/4 cups water to a boil. Pour over tabbouleh in a bowl; cover with plastic wrap for 5 minutes. Uncover and add oil, cucumber, tomatoes, lemon juice, salt and parsley; gently fluff with a fork, incorporating all ingredients.
Spread hummus into the bottom of a 13 x 9 x 2-inch dish. Scatter 1 cup of the feta on top. Layer with tabbouleh mixture. Sprinkle remaining 1/2 cup feta on top.