There is a setting 'Always link course sections' linkcoursesections in Site admin / Appearance / Navigation which, if enabled, results in topic section links e.g. https://moodle.org/course/view.php?id=5#section-2
Thanks for the advice Helen. That setting is enabled, but is the link to the Section, rather than a link to the individual Topics within it.
Unfortunately we have a hugely long Course, with a lot of content that is being used by different teams. (Yes, yes, I know - we should organise the content better!).
I am currently having to rely on the Section link, but then having to describe how to access the specific topic within that. It would be so much easier if I could just link to it!