Relations stored in Database

Hi there!
Thank you for developing this great plugin. May I ask where the information about what content is in a folder is stored?
We have some pages organized in a specific folder. I need to read via PHP what pages are stored in this folder, but I couldn’t find it in the data base. Where would I have to look in the database, to find out in which folder a page is saved?
Thank you for any help! ??