Employees only see that information which they are permitted to see. Permissions can be granted to company departments, workgroups, individual users, or to users assigned to pre-defined roles (moderators, group owners, observers, responsible persons, etc.).
Bitrix 24 lets you show or hide workgroups, documents, CRM contacts, and practically any other item in the system. Access permissions also work in search; that is, search results to which a given user does not have access will not show up in the search suggestions or results.