You can also use WinRAR or The Unarchiver (for macOS) to open split archives.
To access the contents, you generally need of the archive (e.g., .001 , .002 , .003 , etc.). 274674274.7z.001
Often found on community forums or archival sites where large datasets are split into smaller chunks for easier uploading and downloading. You can also use WinRAR or The Unarchiver