My question is fairly basic and I'm struck that it hasn't been asked before on emacs.SE as far as I can see:
How can I see all links pointing to a header at point? This should also include links across files in
org-agenda-files and links using
CUSTOM_ID properties. Is there maybe some built-in function that I've missed?
A similar question has been ask years ago over at SO with a focus on single buffers: https://stackoverflow.com/questions/9844154/list-all-inbound-links-to-a-header-in-org-mode
The answer provided there can only recognize links that use the title of a header.