Next, import the XML file that you just created. When the import screen appears, check the box labeled "Create copy of imported object (this is only supported for exported XML files that contain a single top-most object being exported)". This will import the xml file as a copy of the existing item. If you do not select the checkbox, the import will overwrite the existing item.
Please note that this "create copy" feature will only work when importing an XML file that contains either a single folder as a top-level object, or a single content list object. If you wish to import multiple Content List objects, therefore, they must be exported in a folder, not as a collection of individual objects. The exported folder can then be re-imported as a copy.
As a quick example, if your original folder is called "vacation request", the XML file you create through export will be called "vacation_request.xml", and the new content list folder you create through importing the XML file will be called "vacation request copy".