I do not know of any native green screen command but have used iNav to display this for years. Just start iNav and under the i5 your working on, open File Systems then Intergrated File System. Expand the Root to view all the directories. Right click on the directory you want to view then select Properties. The total Files and Folders will be listed under the Storage tab next to Contents.
Use the command RTVDIRINF, prompt, and enter the directories you want information on. The helps will guide you through this and tell you the naming convention of the outfile that will be created. You can query it or use PRTDIRINF for a report..