If you have chosen to purchase the Extended Access add-on service, it is possible to generate a WebDAV password for access via a network drive to sub-users' My Files and Shared Files. You can enable this feature under Account/Team Settings when logged in to an administrator account.
See What settings should I have if I connect via network location/WebDAV (business only) - Storegate Support and enter the password created for privileged access.
NB. Consider privacy aspects towards sub-users.
