How do I make a hyperlink within a Word document to another place in the same document?

You have to create the place you want to link to as a "Top of Document", "Heading", or "Bookmark".

In the screenshot, I created 123 as a "Heading", and then right-clicked my "Test" text and clickedHyperlink>Place in this document, and you will see 123 there. To do it as a bookmark, highlight the target text, and go to Insert>bookmark, and it will also then show in the Hyperlink area.

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