Hi,
It is possible to have 2 surveys, or 2 completely different applications, edit the same tables. If wanting 2 surveys to do, you would need to have at least one configured by using an existing feature service; see Use Survey123 with existing feature services—Survey123 for ArcGIS | ArcGIS . With 2 applications, you could create the survey as usual, and then add the feature layer of the survey in the other application (or in the map of the other application).
One to note if the applications are editing the same data is that the last edit will 'win' if multiple applications are editing the same feature at the same time; this may cause some issues, especially if you are editing while disconnected, as data that has been edited in one application but not updated in another may be overwritten by the non-updated application.
