[blither]

gremlintv2, да, было б хорошо разнести на строки и разделить этим бат файлом

conceptGrp.bat

Код:

@echo off
SetLocal EnableExtensions EnableDelayedExpansion
  Set src=in.xml
  MD out
  Set C=0
  For /F "tokens=1 delims=[]" %%? in (';find /i /n "<conceptGrp>" ^< "%src%"') do set /A C+=1& set ArrFrom.!C!=%%?
  Set C=0
  For /F "tokens=1 delims=[]" %%? in ('find /i /n "</conceptGrp>" ^< "%src%"') do set /A C+=1& set ArrUntil.!C!=%%?
 
  For /L %%? in (1,1,%C%) do call :CutLines "!ArrFrom.%%?!" "!ArrUntil.%%?!" "%src%" "out/%%?.xml"
pause
Exit /B
 
:CutLines [From] [Until] [SourceFile] [DestinationFile]
  SetLocal
  For /L %%C in (%~1, 1, %~2) do set "txtmask=!txtmask!\[%%C\] "
  (for /f "tokens=1* delims=]" %%a in ('find /v /n "" ^<"%~3"^| findstr /B "%txtmask%" 2^>nul') do Echo=%%b)> "%~4"
EndLocal& Exit /B

И увы notepad++ "Не отвечает"