The StaffSearchResultsDisplayBranch preference is listed in the manual's system preferences, but it is not mentioned in the search results section of the manual (https://koha-community.org/manual/24.05/en/html/searching.html#search-results). You won't know it exists as an option unless you search the system preferences for it directly. Many consortial libraries need to know about the setting, so it seems appropriate to cross-reference elsewhere.
Good spot! Thanks for logging this one, Michael. It will be straightforward to add a link (especially with the information provided) so marking this one as good for beginners.