DirectorySlicer can split or divide files of a folder into partitions of a specified size, while retaining the structure of your subfolders.

How to use:
Folder Hatchet is used to devide the content of a directory into many folders, while retaining the structure of the subfolders.
Simply select or drag-and-drop a source and a destination folder, specify a maximum size for the targeted directories and press START. The size has to be at least as large as the largest file form source folder.

The license of this software is Free, you can free download and free use this file management software.