Back button of Google Chrome after clicking a hyperlink whose target is on the same PDF document
AFAIK there is no way to do it with the standard Chrome PDF Viewer. Take a look at their support page https://support.google.com/chrome/answer/1060734. You could try requesting this feature but keep in mind that the PDF viewer is part of Chrome, not Chromium.
I think it is simpler to just open the hyperlink in a new tab e.g. with the middle mouse button. Then you can just close the tab afterwards.
Alt + Left should be what you want.