I’m trying to access the contents of two_and_one_1.7z , but I’m running into some issues.

Use this for internal documentation or a forum thread where you are explaining what the file is.

If you see files named .7z.001 , .7z.002 , etc., these are split volumes . You must download all parts and use the 7-Zip "Extract" command on the first file to recombine them.