Project Workplan Security

Hi,

We need to restrict acces to several task of a project workplan. Is this possible?

For example: If having Project A with 5 Workplan tasks and 2 key members: M1 and M2.

M1 is task manager of the 1, 2 and 3 task.

M2 is task manager of the 4 and 5 task.

Can we make M1 key member to see only the 1,2 and 3 tasks and M2 to see only the 4 and 5 tasks?

Or is it possible to restrict the acces according to the outline level of the workplan tasks?

If having 3 levels in the workplan, we need to give acces to a certain user to see only the 2 and 3 level, and not the first level.