Please try the SQL given below. This SQL is NOT tested, but should return records with origin_service == destination_service. Please refer to Subqueries with ANY, IN, and SOME

SELECT 
    a.stop_reference, 
    b.service_id, 
    distance(PointFromText('POINT($origin)', 27700),east_north), 
    c.route_number 
FROM 
    bus_stops a, 
    service b, 
    routes c 
WHERE 
    distance(PointFromText('POINT($origin)', 27700),east_north) < 200 
    AND 
        a.stop_reference = b.stop_reference 
    AND 
        b.service_id = c.service_id 
    AND
        b.service_id IN (
        SELECT 
            DISTINCT e.service_id 
        FROM 
            bus_stops d, 
            service e, 
            routes f 
        WHERE 
            distance(PointFromText('POINT($dest)', 27700),east_north) 
+< 200 
            AND 
            d.stop_reference = e.stop_reference 
            AND 
            e.service_id = f.service_id 
        ORDER BY 
            e.service_id, 
            distance(PointFromText('POINT($dest)', 27700),east_north) 
    )
ORDER BY 
    b.service_id, 
    distance(PointFromText('POINT($origin)', 27700),east_north)
[download]

--VC