There used to be a plugin called Block-ref-count that showed a small number to the right of headings representing the number of times the heading was linked to. That plugin is no longer maintained. On the GitHub page it now steers your attention towards the Strange New Worlds plugin by @TfTHacker. It seems very cool; but, as far as I know, it currently has to be installed using BRAT. I may be wrong. Anyways, here is a link to a description: Obsidian October 2022 daily progress and learnings - #13 by TfTHacker. I am not 100% sure that it accomplishes the same thing as the old Block-ref-count plugin, but I imagine there are some here who could expand on whether it meets the use case of @qiaoxingxing. Thanks!