First Item
First Item's 1st sub-item
First Item's 2nd sub-item
Second Item
Second Item's 1st sub-item (*required)
Second Item's 2nd sub-item
Second Item's 3d sub-item
Third Item
Third Item's 1st sub-item (*required)
Third Item's 2nd sub-item
Third Item's 3d sub-item
Third Item's 4th sub-item (*required)