BP determination in checklist step using Rule Policies

Hi gurus,

I've a problem with the bp determination asociated to PPOMA_CRM.

I've configurated in my solman the org structure but I do not know who to make a policity rule.

What I want is to get the bp responsible from a bp (parameter).

For example

org unit root

     + org unit2

          + position 1

               + bp 1 (parameter)

          + position 2 (head of the unit org)

               + bp 2 (boss)

          + org unit 4

          + org unit 5

               + position 3

                    bp 3 (parameter)

     + org unit3

My idea:

case 1: If I execute the rule policy with bp 1, it should determine bp 2.

case 2: If I execute the rule policy with bp 3, it should determine bp 2.

Does anybody if is there a rule what I could do this and associate to my rule modeler profile (so I can use it in my checklist).

Thanks in advance.

Regards