Various playlists formats can be typically converted between one another and .xspf (XML shareable playlist) and .m3u8 are not exception in this. You can either do that using a media player that allows for import/export of playlists, or with some kind of dedicated playlist editor software.
Convert XML Shareable Playlist Format to UTF-8 M3U playlist.
We found 3 software records in the database related to .xspf to .m3u8 file format conversion.
Microsoft Windows software - convert xspf to m3u8 on Windows
One of the most popular multi-platfom multimeda player
Convert from xspf file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned xspf to m3u8. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert xspf to m3u8 on OS X
Mac version of the popular VLC player
Linux/Unix software - convert xspf to m3u8 on Linux
Linux version of popular VideoLAN player