The releases page itself is actually the location to retrieve the hotfix builds separately. The branches contain the final version of each of those builds. So in your case, you can go to the releases page here, download the specific build required, then you can navigate to the local repo on your drive once you’ve unpacked it via Add local repository under File.
https://github.com/EpicGames/UnrealEngine/releases/tag/5.4.2-release
