If you already have the video files and just need the subtitle files (.srt), you can check dedicated subtitle repositories:

While The Simpsons is dubbed in many languages like Spanish and Japanese, it is rarely dubbed in Croatian. Consequently, these subtitled "Hrvatski, Engleski" versions are the primary way the show is consumed in the region. Where to Find Subtitles

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".

This version is specifically sought after by Croatian speakers because it contains dual-language subtitles, allowing viewers to watch in the original English while following along in Croatian.

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