Data Segregation

Hi All

I am looking to create 2 business units in CRM 2016 to be able to segregate. I am looking to do the following:

1. Create 2 Business units named A and B

2 I will have users in Business Unit A and these users should not be able to see what data is in Business unit B and as for users in business unit B these users can see across all business units.

so in the event that contacts owned by users in Business unit A are marketed to by users in Business unit A express interest in newsletters from Business Unit B and if users from Business unit B send the marketing communication to contacts owned by Users in Business Unit A.

Is there a way to stop users from Business Unit A seeing marketing communication sent to contacts they own sent by users in Business unit B

Any ideas and solutions welcome