Restricting contracts access

Summary

Is there a way to restrict users to view contracts created within their business unit

Content

We have a requirement to restrict the users to view the contracts created in their own business unit or organization which is assigned in his/her resource definition.

Currently user is able to view the contracts created outside his/her assigned business unit but cannot make amendments.  User can Amend only those contracts created under the assigned org / BU.

Any pointers would be highly appreciated.  

Thanks,