showing / hiding folders in the file manager for lower level admins

Hi,

I could not find a way to customize which folders an admin user can see under the Files tab. I would like to hide the core,manager,assets folder from a certain admin group. Anyone have a tutorial? I already have the file structure so that there are folders on the same level as the assets,core,manager folders that need to be accessed by the admin. The site is already done, and these other folders are already in use, so I can’t reorganize the folder structure without causing a headache. Therefore, I thought there must be a way just to mark folders as hidden for specific user groups?

Thanks