This wiki article explains the "Export Settings" available, in the "Design File Settings" dialog box.
From the CAD menu, go to "Settings > Design File". Select the category "Civil Formatting", to get the civil settings.
Importance of "Export To Native" setting : There are two options here, 'Use Feature Setting' and 'Manual'. This option helps keep a version of the native geometry database, in sync with civil geometry stored within the design file. This option controls whether Civil Geometry is exported to the native database automatically or not. When set to 'User Feature Setting", any civil geometry elements will be exported to the native database when stored with a feature that has 'Export to Native' option set to "True".
When the setting is set as "Manual", civil geometry elements can only be exported to the native database via a manual export.