Business Partner Relationships?

Hi Gurus,

I want to join/tie two business partner to each other.I mean when I check all debts for one partner I also want to see the other ones debts in their contract accounts on FPL9 or any screen, because there are two partner created in SAP for just one person.Is it possible with relationships feature in tcode FPP2, or any other way to do it? Also what is the point of relationships for partners, I used "is identical to", but it is not worked, how we use those property, and where the relationships stored in tables?

Thanks for your helps.