You get this by going to the Octane menu at the top of the C4D interface and choosing Live Viewer. This is the heart of Octane Render, and how you’ll be interacting with Octane in C4D most of the time. It’s designed to work hand in hand with the manual and help with discovery (wait, it can do that?!) and grouping categories of things together so you never have to say “where was that again?”. It’s meant to be an easy, searchable reference that shows where everything is and what it all does, all in one place.
This guide is closely related to the Getting Started With Octane Render for C4D walkthrough.