I am working with a multi-company setup in Odoo where we have Company A and Company B. Currently, both companies share the same mail contacts and mail campaigns in the email marketing module. However, we need to completely separate these elements so that each company can only see and manage their own contacts and campaigns.

Specifically, we want to ensure that:

1. Company A's users can only see and manage their own mail contacts and campaigns
2. Company B's users can only see and manage their own mail contacts and campaigns
3. Mail contacts from one company should not be visible or accessible to the other company
4. Mail campaigns created by one company should be completely separated from the other company

Is there a way to implement this separation using Odoo's multi-company features? We need guidance on:

• The proper configuration settings required
• Any necessary model modifications
• Security rules or record rules that need to be implemented
• Best practices for maintaining data separation between companies

Has anyone implemented a similar setup or can provide guidance on achieving this separation?