User on Bentley communities: I have found some issues with complex Revit family such as trusses. After the export through a plug-in to Synchro, the trusses are no longer available to select as one object, but they are exploded into all elements (beams, posts, struts) created from.

Attached is an image of user showing the system family in Revit and how the trusses is selectable as one component in Revit.