FileNameTake

FileNameTake["name"] gives the last path element (filename) from a path.

FileNameTake["name", n] gives the first n path elements.

FileNameTake["name", -n] gives the last n path elements.

Examples

Get filename:

FileNameTake["/path/to/file.txt"]
(* "file.txt" *)

Get parent directory:

FileNameTake["/path/to/file.txt", -2]
(* "to/file.txt" *)

Please visit the official Wolfram Language Reference for more details.