You can choose, that the parent is visible and got the first option chosen, or all options, so the customer can see e.g. the most used case.
The dependency goes from the first to the last field, so it's on you to make a logical structure your customers can follow.
One way would be to display the second field only if the first is chosen. But there are a lot of ways so you have to find the best for your specific task.
Regards
Stefan