You can run the report from NS 7 if the service account used by NS 7 to run the report has access to the SEPM databases. You could actually put any SQL report there provided the account had access to the databases.
To use a simple example, you could execute the following report from NS7:
SELECT TOP 5 * FROM sem5A.dbo.[V_SEM_COMPUTER] where sem5A is the name of your database for SEPM A.
This assumes the same SQL server hosts SEM5A that hosts your Symantec_CMDB database for NS7. If it's a different server, list it out:
SELECT TOP 5 * FROM sql_prod_016.sem5A.dbo.[V_SEM_COMPUTER] where sql_prod_016 is the name of the SQL server and the instance is default.
Once this works for one database, add the second, then join using UNION ALL:
SELECT TOP 5 * FROM sql_prod_016.sem5A.dbo.[V_SEM_COMPUTER]
UNION ALL
SELECT TOP 5 * FROM sql_prod_016.sem5B.dbo.[V_SEM_COMPUTER]
You may want to add a column to specify source:
SELECT TOP 5 *,'SEPM A' as 'Source' FROM sql_prod_016.sem5A.dbo.[V_SEM_COMPUTER]
UNION ALL
SELECT TOP 5 *,'SEPM B' as 'Source' FROM sql_prod_016.sem5B.dbo.[V_SEM_COMPUTER]
Does this help answer how you might query the SEPM databases from within Altiris?