You can export files or complete folder structures by selecting them and choosing Save to... from the File menu. You will be presented with a dialog window that will ask you which revisions to save; the current revisions or a set based on a label. If this section is greyed out it means that there are no labels attached to any of the document revisions in the selected project, folder or document and therefore only [current] revisions are available to export.
It will also ask you to select a destination folder on your local system. The selected ITP/MDK Repository folder structure will be saved to this local folder, maintaining the exact folder organization.
Compiled models do not get exported if you export a folder or a document. If you want to export compiled models you must deploy them. Text Blocks, Content Wizards, Forms, Views, and Field Sets are not exported.
Refer to Save to.../Load from for more information.