Explanation:

•   findstr "not found /source": Filters lines containing /source.
•   for /F "tokens=3 delims= ": Extracts the 3rd token (file path).
•   for /F "tokens=* delims=/": Splits the file path by / and extracts the last token.
•   %~nB: Extracts just the file name (without extension).

2. Remove Duplicates

Pipe the output to sort /unique to remove duplicates:

findstr "/source" logfile.txt ^ | for /F "tokens=3 delims= " %A in ('findstr "/source" logfile.txt') do @for /F "tokens=* delims=/" %B in ("%A") do @echo %~nB ^ | sort /unique