I want to see in which folder this paper is sorted

When browsing in the 'All Documents' folder, I'd like to know in which folder the file is sorted. Say there are folders 'A','B','C' in Mendeley desktop, and I put 'a' paper into folder 'A'. Later when I am at the 'All Documents', is there a way to know where 'a' paper is located? I could see folder 'A' was shaded when I click 'a' paper so I could know 'a' paper is put into 'A' but now it is not showing any change... Thank you :)