By default, sharing is inherited from the top down. If a task, folder, or project is shared with a user, then all items added to or created in that task, folder, or project are also automatically shared with that user. With inherited sharing, you can't unshare a subtask, subfolder, or subproject from users if they have access to the parent task, folder, or project.
Turning on selective sharing for a folder or project lets you edit who can access that folder or project, regardless of who has access to the parent folder or project. When you turn on selective sharing for a folder or project, it remains shared with any users who had access to it at the time that selective sharing was turned off.
When you turn on selective sharing, the folder/project is no longer automatically shared with additional users when you:
Share the parent folder/project with additional users.
Add the folder/project to another folder/project, or move the folder/project from one folder/project to another.
Any subfolders or subprojects added to the folder/project with selective sharing turned on will follow the logic of inherited sharing — unless these new subfolders/subprojects also have selective sharing turned on.
Regular users on Enterprise accounts can turn on selective sharing on folders or projects where they have Full access.
Navigate to the folder or a project for which you want to enable selective sharing.
To access the sharing menu:
Right-click a folder/project from a space folder tree and select Share, or
Open a folder/project info panel and click the Shared icon.
Click Advanced settings in the lower right-hand corner of the pop-up window.
Selective sharing is now turned on for the selected folder or project. You can reenable inherited sharing at any point by going through the same steps and clicking Enabled in step 4.