Query All Files
With the new Query All Files permission, View All Data users can query ContentDocument and ContentVersion and retrieve all files in the org, including files in non-member libraries and files in unlisted groups. On its own, the View All Data permission only allows you to query files you own or have access to.
Where: This change applies to Lightning Experience and Salesforce Classic in Professional, Enterprise, Performance, and Unlimited editions.
How: Enable the profile permission under System Permissions and App Permissions in Setup.