If you already have the video files and just need the subtitle files (.srt), you can check dedicated subtitle repositories:
The "feature" you are referring to is likely a specific used on torrent sites and media libraries (like Plex or Jellyfin) to indicate that a release of The Simpsons includes both Croatian (Hrvatski) and English (Engleski) subtitles . Key Features of this Release The Simpsons (1989) Hrvatski, Engleski titlovi
: A popular site for Balkan language subtitles (Croatian, Serbian, Bosnian). If you already have the video files and
It refers to the original 1989 series created by Matt Groening, which premiered on December 17, 1989, with the Christmas special "Simpsons Roasting on an Open Fire". which premiered on December 17