Am I to understand that you created a folder with in it several sub-folders (for each individual movie)?
And that you subsequently defined all those subs-folders (directories) under
(rightclick >) Options > Preferences > Subtitles [Subtitle properties]?
Then the file you're interested in is
BSplayer.xml. How do I save my personal settings?
P.S.:
(Another file which might be of interest - depending on what exactly you did and/or intend to do - is
bsplay.sav)