Hi Pradeep Chouhary,
The Site Systems tab will remain empty until the boundary is associated with a boundary group that has a site system assigned. Boundaries themselves do not directly hold site systems; they must be linked to a boundary group, and then that group must be configured to include your new SCCM server as a site system. Go into Administration → Hierarchy Configuration → Boundary Groups, create or edit the relevant boundary group, add your boundary, and then under the “References” tab assign the new site system server. Once that is done, clients within that boundary will correctly resolve to the site system. If you’ve already done this and it still shows empty, confirm that the new server has the SMS Provider role installed, that it is publishing to Active Directory (check System Management container permissions), and that the site system roles such as Management Point and Distribution Point are properly installed and healthy. This configuration is what ties boundaries to site systems, not the boundary object alone.
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Harry.