I would need a query that returns relation between objects:

ob_1  ob_2
1    2
2    3
3    4
4    5
5    6

If I wanted to know how 1 is related to 6 it would return:
1-2-3-4-5-6

If I wanted to know how 3 is related to 1 it would return:
3-2-1

If my example was set up differently even two different possibilites of relations might show up.

Thanks