SdFat - howto determine the fully qualified name of a file?

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:

          sub-dir_AA /
                      sub-dir_AAA /
          sub-dir_AB /

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).