When you want to get a file name from long file path, you can use a method fileNameSplit() which you may find in Global class.
This method returns a container, where the first value is a path, the second file name (without extension), and the last third one is an extension.
You have to remember that path is returned already with last backslash '\', so for example C:\Test\
And also what is important, that last value (extension) is returned with dot '.', for example '.xml'
An example of code below
static void SplitFileName(Args _args)
{
Filename fileNameOrig = @'\\NetworkPath\In\FileName.xml';
fileName filePath;
Filename fileName;
fileName fileExt;
[FilePath, fileName, fileExt] = fileNameSplit(fileNameOrig);
info(FilePath);
info(Filename);
info(fileExt);
}
And a result