This recent post solved how to iterate for files in all sub-directories:
Looking at the diagram below, my code can determine file1's name and its immediate sub-directory sub-dir_AAA:
/subdir_A/
sub-dir_AA /
sub-dir_AAA /
file1
sub-dir_AB /
file2
file3
Is there an API that provides the fully qualified name for file1, ie /subdir_A/sub-dir_AA/sub-dir_AAA/file1? If not, I will have to perform this programatically (which is not as neat).