Sadly, access via WebGui has been disabled on 08.09.2023, see https://blogs.sap.com/2017/12/05/new-sap-gateway-demo-system-available/ .Therefore the first unit of this tutorial is not relevant and I recommend to update it. I was thinking about using Eclipse for checking the hierarchy visually, but you might have a better idea (as Eclipse is slowly but steadily being dropped off by SAP, too).
Tutorials: https://developers.sap.com/tutorials/odata-02-exploration-epm.html
Sadly, access via WebGui has been disabled on 08.09.2023, see https://blogs.sap.com/2017/12/05/new-sap-gateway-demo-system-available/ .Therefore the first unit of this tutorial is not relevant and I recommend to update it. I was thinking about using Eclipse for checking the hierarchy visually, but you might have a better idea (as Eclipse is slowly but steadily being dropped off by SAP, too).