There are the following options:
remove shares for single persons or remove a public link
remove all existing permissions for a file or a folder in the Drive app
The following information about folders can also be applied to address books and calendars.
How to remove shares for single persons or remove a public link.
In the folder tree, select a folder that you shared.
Click the iconnext to the folder name. Click on .
In the Drive app, you can also click the icon in the toolbar. Click on .
The window for adjusting the permissions opens.
Click the iconon the upper right side. Click on in the menu.
Click on .
How to remove all permissions for a file or a folder in the Drive app
In the Drive app, open in the folder tree.
Select a share in the detail view. Click on in the toolbar.
Also see
Parent topic: Sharing