try this --
SELECT Parking
FROM Bus
WHERE Bus.BusNumber=::BusNumber::
UNION ALL
SELECT *
from ( select Parking2 From Parking1 order by parking2 )
or perhaps something like this
SELECT 1 as sortkey1
, ' ' as sortkey2
, Parking
FROM Bus
WHERE BusNumber=::BusNumber::
UNION ALL
SELECT 2 as sortkey1
, Parking2 as sortkey2
, Parking2
From Parking1
order by sortkey1, sortkey2
rudy