: Ensure you have part1.rar in the same folder. Opening part1 with a tool like 7-Zip or WinRAR will automatically pull the data from part2.rar to complete the extraction.
: If you downloaded this from a third-party site, check the file size against official DLC data to ensure the archive isn't corrupted or incomplete.
: The official page for the Battlefields DLC provides the most reliable context for what is included in these files, such as new missions and the level editor. Tips for Multi-Part RAR Files