As far as I see from the code, the LightScene data is writte to a file, wich is written in the same directory as the statefile, with the name LightScenes.save. The default should be log/LightScenes.save in the /opt/fhem directory. If you are using configDB, then this file is written to the database, see the configDB help on how to extract it.
I might be wrong, as I never used LightScene.