Nevermind. A few minutes after I asked, I found it in the demos of Essential Studio -> Explore Demos -> PdfViewer. The only thing that is different are some naming of elements as far as I can see after a few minutes, but this is also the case in the tutorial.
KKKarthik Krishnaraj Syncfusion Team December 24, 2018 05:34 AM
Greetings from Syncfusion,
We have added simple code snippet in the user guide documentation to create custom toolbar for PDF Viewer control and accessing the APIs of our control. We are using more styles for alignment and PathIcon for toolbar in the attached sample in UG. If we include those details in the UG, then it will look clumsy. So, we have included the basic details. However, we will do the modifications as per your feedback in our next release.