You can securely share content stored in enterprise repositories like SharePoint, OneDrive, Box, and others with third parties by using a platform that offers secure and compliant channels for sharing. Ensure that the platform allows you to enforce role-based sharing policies, maintain source permissions, and provide visibility and control over who has access to sensitive enterprise content. The platform should also contain security features like access controls, multi-factor authentication, encryption of all content in transit and at rest, data loss prevention (DLP) integrations, and others.