To manage NFS exports, first select the NFS service from the Services menu. You can then select the NFS servers you wish to manage from the Server tree. Any exports available should be listed in the main pane. If there are no exports, the main pane will look like this:

To add a new export,

1. Click the "Add new export" button. This will display the Add New Export screen:
2. Enter the directory on your server or servers you wish to export. Then, select the desired parameters. Once the export is configured, click the "Save" button. This should return you to the main Exports screen to apply your changes:
3. To apply the changes now, click the "Apply changes now" button.
   
4. To schedule the change, click on the calendar icon to pull up a calendar to choose the date and time you wish the change to occur. You can do this by entering the time, then clicking on the appropriate date. Then, click the "Apply changes at" button to schedule the change.