Multiple captions in one storyline file?

I see, thanks for confirming that! 

You can use the translation feature to generate caption text in different languages. However, you can only use one set of captions per video/audio file. You may be able to use separate layers or slide branching to include all translated versions in one Storyline file. 

Hopefully other folks who have used this kind of set-up can share their experience with you here!