Hi Bryan,
FYI, if you're using ArcGIS Enterprise 10.6 or later, Portal for ArcGIS includes Operations Dashboard for ArcGIS. In which case, you wouldn't need to move your Survey123 data into ArcGIS Online.
> How do I get the feature service and map to populate the survey results in operations dashboard?
Please take a look at the Distributed Collaboration capabilities between ArcGIS Online and ArcGIS Enterprise,
Distributed collaboration—ArcGIS Online Help | Documentation
You could migrate the Survey123 data into ArcGIS Online. Then it could be used by Operations Dashboard in ArcGIS Online.
Hope this helps,