how to restrict the approve by based on projects

Hi Experts

I have configured ChaRM in solman 7.1 sp12.  here we have multiple systems and multiple project managers.

we have created the project based on the landscape, now the customer wants to restrict the authorization based o the project.

I have checked in the change manager role but i didn't able to find the authorization.

Could you please help how I can resolve the issue.

Thanks & Regards

Venkat