PL/SQL :: Obtains A List Of Paired Entry

Variation of a post I entered last week.I have 2 queries, 1 obtains a list of paired entries, and the other for a given pair of entries returns a list of common locations.Both these queries behave exactly as I expect (although trimmed significantly for this example)With C++ code, i can recursively work through the results from query 1, and plug them into query 2, but this has a large time overhead.Preference would be to nest the queries so result is extracted during 1 connection, and not constantly requerying the database for additional sequences.

SELECT     SWTT_HEADER.THR_ID AS S_HDR, DWTT_HEADER.THR_ID AS D_HDR
FROM         RTDEV.TRIP_HEADERS SWTT_HEADER INNER JOIN
                      RTDEV.TRIP_HEADERS DWTT_HEADER ON SWTT_HEADER.TRIP_NAME = DWTT_HEADER.TRIP_NAME
WHERE     (SWTT_HEADER.TME_ID IN (1)) AND (DWTT_HEADER.TME_ID IN

(2))Query 1 above gives me exactly the trip pairs I need, can range from 1 pair to a few thousand..Query 2 below gives me the common locations for a specific pair as extracted line by line from query 1.What I am looking for, is how to combine these 2 queries so that the values of THR_ID in query 2 are recursively pulled from query 1.

SELECT DISTINCT DWTT_BODIES.MASTER_NODE AS LOCN
   FROM RTDEV.TRIP_HEADERS SWTT_HEADER
        INNER JOIN RTDEV.TRIP_HEADERS DWTT_HEADER
           ON SWTT_HEADER.TRIP_NAME = DWTT_HEADER.TRIP_NAME
        [code]...

From the sample data, i expect query 1 to return pairs 1,9 2,10, 3,11 4,12 5,13 6,14 7,15 and 8,16
Entering 1 and 9 (first pair) as the THR_ID values in query 2 will yield B,C , as these 2 locations are common to both trips.
Entering 2 and 10 (2nd pair) as the THR_ID values in query 2 will yield G,H , as these 2 locations are common to both trips.

The aim is to achieve B,C,G,H from a single query.I figure if I can write C++ code for it, there has to be an SQL shorthand?