How to bulk add folder name to file name?

Question

I have a folder struktur like this:

/1/1/master.jpg
/1/2/master.jpg
/1/3/master.jpg
/2/1/master.jpg
/2/2/master.jpg
/2/3/master.jpg
...

Answer 1

@echo off
setlocal EnableDelayedExpansion
cd C:\Parent\Folder\OfFirstNumberedFolders
for /F "delims=" %%a in ('dir /B /S /A-D master.jpg') do (
   set "fullName=%%a"
   for /F "tokens=1-3 delims=\" %%b in ("!fullName:%CD%=!") do (
      ECHO ren "%%a" "%%b_%%c_%%d"
   )
)