While "Pathfinder" is not a standard edition name for the game, you may be looking for specific expansions or DLCs available on GOG:
GOG provides DRM-free versions of games, meaning you truly own the copy you buy. You can download the installers and save them to external media (like a USB or DVD) to install them whenever you want without needing an internet connection or a launcher. Distant Worlds 2 on GOG.com Download Distant Worlds 2 Pathfinder-GOG
Click on the button or look for the "Download offline backup game installers" section. While "Pathfinder" is not a standard edition name
: Focuses on high-tech research and hive-mind swarming tactics. : Focuses on high-tech research and hive-mind swarming
You can manage settings like language by clicking the (top bar) → Manage installation → Configure . Via Standalone Offline Installers : Log in to your account on the GOG website. Navigate to your Library and select the game.
: Adds new psychic abilities, mega-ships, and the Shakturi threat.