I would like to group layers in the table of contents in the map ArcGIS Portal 10.3 but I don't see a way to do this. Is it possible? When I group layers in ArcMap and then publish to ArcGIS Server, I get the message:
standalone table's data source is not supported
...but I am able to publish these layers separately (they are in Oracle). So it looks like I have to group them in the table of contents in Portal.