FileExtension("a.txt") > txt
FileExtension("files/folder/a.txt") > txt
FileExtension("files/folder/") > 
 GetFileNameFormPath("files/folder/a.txt") > a.txt
 GetFileNameFormPath("files/folder/") > 
 GetDirectoryNameFromPath("files/folder/") > folder
 GetDirectoryNameFromPath("files/folder/a.txt") > folder
 GetDirectoryNameFromPath("files/folder/a.txt") > 
 GetDirectoryPathFormFilePath("files/folder/") > files\folder/
 GetDirectoryPathFormFilePath("files/folder/a.txt") >