Silly question #1
Are there limitations associated with these nodes, the "Department" custom property or the user account and/or group that's trying to view the nodes?
Silly question #2
What's the NCM role for the user or user group trying to view these nodes?
Answer#1 : The user account can view all core devices, having admin rights. also core devices include all departments.
Answer#2 Its my account i.e. Administrator .
Its happen after upgrade to MCN 7.5 before this I can view and download config manually if required.