Making tasks visible only after you have completed a prerequisite

Hi Guys,

I know this is not the 'normal' use case of a todo list, but...

Is there any way to make a task visible only after you have completed a precursor. I want to write a list of tasks that have to be done in order. And it's important the future tasks are invisible.

Example task list: A B C

When someone is added to this task list (sublist). She sees: A After completing A, she sees A B

After completing B, she sees A B C

Pekaboo with the api could work. Setting the boolean for Pekaboo for B and C when the previous task is completed. But how do we make it so that we know when a task is completed? With webhooks?