"Information transfer rules, procedures, or agreements shall be in place for all types of transfer facilities within the organization and between the organization and other parties."[1]

To help protect the organization's data you must control it's transfer within the organization and to external organizations. Firewall rules can restrict data transfers between your networks. Sharing restrictions on cloud resources like SharePoint also help protect data from unauthorized transfers. Service agreements with external organization can also cover data transfers by restricting transfers to authorized methods or channels.