How to design two custom Supplier roles with BU-based data security

Summary:

I need to design two custom roles in Oracle Fusion Cloud for Supplier Sites with different access levels based on Procurement Business Unit (BU). The same user should have both roles:

• Role 1: Read-only access to Supplier Sites for Procurement BU = US.
• Role 2: Edit access to Supplier Sites for Procurement BU = CA.

The user should only view US sites and edit CA sites.

Content (please ensure you mask any confidential information):

• What is the correct secured object and actions to use in Data Security Policies for Supplier Sites (View vs Manage)?

• How to define instance sets and conditions to filter by Procurement BU?