Open task2 once task1 completed?

[Van Dijk]

Is there possibility have a subtasks "in the relation" to each other, like once task1 is completed it will open task2. So you cannot work (or see) the task 2 unless the task1 is completed?

We would really need that kind in some change management process to keep the flow accurate.Some tasks cannot be done unless others are completed and I would like to hide those until can be done.