How To See All Files And Subfolders Added To Shared Folder After Created

I made a work group between 1 window seven PC and 2 window XP PC.In Window7 PC I shared folders and can see them in the 2 window XP all files and subfolders that are already in the folders before were shared. But all the files and subfolders that add after were shared I can't see.I found the subfolders that add after the shared folder was created were not shared and if I shared the subfolder I can see; but with the files nothing.How can I see all files and subfolders added to the shared folder after created?