Select an option in the "Navigate by" widget in the Navigator panel and press F1. This opens [1] at the top of the page. Enhancement: Open the page with "Navigate by" visible (because there is a lot of information on this help page, and not clear what to look for). [1] https://help.libreoffice.org/24.2/en-US/text/swriter/01/02110000.html?System=WIN&DbPAR=WRITER&HID=modules/swriter/ui/navigatorpanel/NavElementWidget#bm_id61683983952550
Reproduced with gen VCL in: Version: 7.1.0.3 / LibreOffice Community Build ID: f6099ecf3d29644b5008cc8f48f42f4a40986e4c CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: x11 Locale: en-AU (en_AU.UTF-8); UI: en-US Calc: threaded Dropdown was made available in 7.0, but "Navigate by" heading first appeared in the 7.1 documentation.
Rafael Lima committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/8dcfe198356b4be518c2de4beb2c2fa92716fed7 tdf#155884 Fix "Navigate By" target in help