FROM CLIENT.qvd (qvd); //Load all clients, even for the clients are not in Section Access table yet
script part 3:
'ALL' as NWGROUP,
Select country from table where country not in (country_a, country_b, country_c);
country_a, country_b, country_c are the country you do not want the manager to have access.
You can check the "*" usage case from the discussion here. You can use "*" if the countries except the 3 are assigned in the section access. Then you can change the section access as below to give the manger access.