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.
Finally I contacted ESRI support. They told me that it is not possible to create groups in ArcGIS Portal 10.3. As well, if you make a group in ArcMap and publish the group to ArcGIS Server, Portal will not display the group. Apparently this is something that is coming soon in ArcGIS Online and eventually will make it to ArcGIS Portal.