[megaloman]

Код:

@Echo Off

Set "In="Z:\Box_In" "Z:\Box_Arc" "Z:\dddddddd" "Z:\Tra La La""
Set "Mask=_????Y??M??D*.mp4"

FOR %%d IN (%In%) DO (
	FOR /F "usebackq tokens=1,2,3 delims=_YMD" %%i IN (`Dir "%%~d\%Mask%" /B /A:-D 2^>nul`) DO (
		If Exist "%%~d\_%%iY%%jM%%k*.mp4" ( 
			If Not Exist "%%~d\%%i\%%j\%%k" Md "%%~d\%%i\%%j\%%k" 
			Move /Y "%%~d\_%%iY%%jM%%k*.mp4" "%%~d\%%i\%%j\%%k\" >nul
		) 
	)
)

или, ИМХО, нагляднее

Код:

@Echo Off

Set "Mask=_????Y??M??D*.mp4"

Call :Trans "Z:\Box_In"
Call :Trans "Z:\Box_Arc"
Call :Trans "Z:\dddddddd"
Call :Trans "Z:\Tra La La"

GoTo :Eof

:Trans

FOR /F "usebackq tokens=1,2,3 delims=_YMD" %%i IN (`Dir "%~1\%Mask%" /B /A:-D 2^>nul`) DO (
	If Exist "%~1\_%%iY%%jM%%k*.mp4" ( 
		If Not Exist "%~1\%%i\%%j\%%k" Md "%~1\%%i\%%j\%%k" 
		Move /Y "%~1\_%%iY%%jM%%k*.mp4" "%~1\%%i\%%j\%%k\" >nul
	) 
)