When you add Octane LiveDB Material in LW Node Editor, there are three buttons on that node's properties, the button Edit Octane Material opens that view :)
See manual page for that here: https://docs.otoy.com/Lightwave3D/?page_id=868

Have fun :)

Antti

Thanks for your quick reply. This got me ...

14 seconds into this tutorial https://vimeo.com/133139422 up pops a screen titled NodeGraph 'Root'. Does anyone know if this is part of LW, Octane or some other separate plugin? If you could let me know where to find it and/or how to access it, I would be very grateful. Thanks