Unfortunately, you can't export the whole document in a standard BPMN 2.0 file, but you can export it in as a XPDL file which is supported by the BPMN utility. In order to export it to XPDL, click the Import/Export tab and select XPDL from the Export group. Select a destination directory and click OK. Also, you need to know that Bizagi allows you to export only diagrams to BPMN 2.0 format. If you want to export diagrams, you can follow the instructions provided by the developer.
