How to restrict access to release planned orders in a Supply Plan based on Planner?

Summary:

 How to restrict access to release planned orders in a Supply Plan based on Planner?

Content (required):

We have a scenario like this

Items A, B, C

Planner X

Items D, E, F

Planner Y

We have defined two supply plans. 

Supply Plan SP1 for releasing Planned orders of Items A, B, and C

Supply Plan SP2 for releasing Planned orders of Items D, E, and F

I do not want Planner X to release any planned orders in Supply Plan SP2

Similarly, I do not want Planner Y to release any Planned orders in Supply Plan SP1

Please confirm how this can become possible.