GP-Rolle in S/4 mit unterschiedlichen Partnerschemen (AG, WE, RE, ....)

Im trying to get used to the S/4 partner rolle technology, but I have got a request for partner function allocation (ship-to party only) to a partner rolle "Ship to partner" (transaction BP), which I simply can't get up and running.

How can I assign a self made partnerscheme (easy in the previous ERP ECC6 based on the account groups) to a new partner rolle "Ship to partner", which I want to create using t-code "BP" ?

Hope someone can help.

Cheers,

Uwe