We are using two modules of CRM, Sales, and Service. Now, there are some users whom we were given access to both the modules and now it means they can see records of both the application.
e.g. for activities, we have an email "A" for Sales and email "B" for Service, now when the user has access of both records he can see both emails. If users go to the Sales app, they can see both the emails and Service. We have the requirement that even if users can see both the emails but if he goes in Sales app then he can see sales-specific emails and same for service too.