Atlas Subtitler has a built in automatism that will select automatically the best subtitles with a high success rate. But it's also possible to select them manually. To activate that put a checkmark in the box Choose from hand. At a download a dialog like this will then appear:
Since the downloaded subtitle files include a language code as part of their file name more than one language can lay aside the video. For each language you can set at most one of the checkmarks. But you can also check none of them.
Initially the list is sorted the way Subtitler thinks is best. On top are the best matches.