Select multiple files to make them private in a project
When private objects are enabled in the settings of a project, you can select multiple files to make them private to your project's guest members.
Select files with your mouse and your keyboard (Ctrl + Click, Click and Shift + Click, Ctrl + a, etc.). When your selection is complete, use the More menu of the Files app or the Contextual menu (Right click your mouse or use the 'm' touch of your keyboard).
In the Private file window, choose to make selected files private or uncheck them to make them visible to guests in your project.
Please note that only files owned by the project can be made private -- this action cannot be completed for shared files (Action not possible for 2 items in the previous screenshot).
To find out more about Private objects, please read this FAQ: Use Private Objects in a project with clients.
Have a nice day,
GroupCamp - Project Management