This might be done using an add-on (which does not exist yet) and via JSON
https://kodi.wiki/view/JSON-RPC_API/v12#...ary.Export
Unfortunately the current JSON implementation seems only support exporting the library to a single XML file (hence the parameter for the path for the file to be written which is required to be set).
Expanding this functionality might be pretty tricky (at least for me). But if, it might be not too hard to write an add-on for that. "Advanced Library Export"
Edit:
I guess I have to correct myself. Looking at the code, it seems one is able to export to separated files as well.
https://github.com/xbmc/xbmc/blob/master...#L965-L988
Will play around with that a bit
Edit 2:
Yes. The code says clearly, if the first additional property is "path" then it will require the path as a string. But that "path"-property is optional and if it´s not given, the executed command is:
exportlibrary2(video, separate, dummy
and one is able to configure the settings what is exported and what not.
I´ll write an add-on for that soon.
For the time being, you could map a button on your remote to execute a specific JSON call to export the library.