If you use BS.Player , it has a built-in feature that automatically searches for and downloads subtitles from multiple online databases when you open a video file. Quick Tips for Better Results
You can also check major subtitle databases such as Subscene or Subdl , which host community-uploaded files for various languages. Yellowstone (2018) Bosnian subtitles
Sites like Prijevodi-online or the Croatian/regional sections of OpenSubtitles are the most reliable sources for Bosnian, Serbian, and Croatian (EX-YU) translations for TV series. If you use BS