xdmp.filesystemDirectoryCreate

xdmp.filesystemDirectoryCreate(
   pathname as String,
   [options as Object?]
) as null

Creates the directory specified by pathname. Returns the empty sequence upon success.

Parameters
pathname	Pathname of the directory to be created.
options	If `createParents` is `true`, then if necessary it will create the parent directories all the way down to the final directory in the path. If `false` it will merely complain that the parents do not exist. The default for `createParents` is `false`.

http://marklogic.com/xdmp/privileges/xdmp-filesystem-directory-create

xdmp.filesystemDirectoryCreate("/tmp/a/b/c",
                               { createParents: true }
                              )