Based on your request, to properly look into a file, you are dealing with a compressed archive, likely requiring specialized software to open and inspect its contents. How to Open/View the Content
If your file is part of a series (e.g., BLP024.7z.001 , 002 ), you must have all parts in the same folder to open it. BLP024.7z
If 7-Zip reports an error, the file header might be damaged. Try opening it in a Hex Editor. Based on your request, to properly look into
How do I search the content of 7-Zip archives (.7z)? - Super User Based on your request
If you need to search for text inside the archive without unpacking it first, this free tool can look inside .7z archives. Important Tips for Handling .7z Files