Hi Stuart,
Dataverse stores natively-created data flows and imported legacy data flows (.brgs) in the Dataverse database. A data flow can be exported from Dataverse (as an archive .lna file) from the Dataverse Directory view.
Select the required data flow in the Dataverse Directory and click the 'More actions" menu in the 'Open' panel (top right of the User Interface) and then select the 'Export...' option.
If required you can output multiple data flows into a single .lna file by selecting the required data flows in the Dataverse Directory and then using the Export button on the 'Open' panel.
Regards,
Adrian