In longer documents, breaking text up into chapters or sections is almost a given.
That doesnt mean its impossible though in fact, in Google Docs, its quite easy.
you could do this by clicking on the point of your text you want to link to.
Next, nudge the Insert button in the top menu, and go down to Bookmark.
Insert menu with bookmark option
A small blue bookmark symbol will appear on the left of your text.
With that, youre ready to link to that section of text.
Select Link from the menu.
Here, you could pick from either headings or bookmarks (or external URLs).
press Bookmarks to reveal a list of the ones youve set.
Link options including bookmarks
Simply pick the right one, and then poke the blue Apply button.
Your link is set, and clicking on it will take you straight to the bookmark you set!