To achieve this, you have to first make sure that the accounts that you want to interact with different users are in the same group. Check this guide for more information regarding groups.
Once this has been done, simply enable group blacklist in the module you want account to interact with different users and check the option Add interacted users to blacklist.
Group blacklists are shared between all accounts in the same group. Make sure you enable the blacklist for each account in the group.