XSPF, short for XML Shareable Playlist Format, uses XML tags to list the path of local audio files or URLs of online streaming media in a playlist, which is similar to M3U, M3U8 and WPL.
XSPF itself doesn't contain any video or audio data. So there is no any third-party tool that can convert XSPF playlist into media formats.
Since XSPF file is XML-based file, which is classified as text file, you can open it with text editors and find the location of the actual files. Just right click on the XSPF file and open it with Notepad or other text editing tools you have. Then you can see where the media files are physically located in the text. Then use a video converter like FFmpeg, or GUI-based Handbrake,Free HD Video Converter, Any Video Converter, etc. to convert your local media files listed in the XSPF file to MP3, MP4, etc.