How to retrieve position from an organisational unit?

Hi All,

Can anyone please help me for the following scenario.

Actually i am trying to read the only the positions under an organisational unit from PPOMA_CRM.I am currently using the function module RH_STRUC_GET and i have found only the evaluation path 'O-S-P' to retrieve the positions. However is also retrieve me with organisational unit

lower in the model hierarchy.

But what i want to know is that if it is possible to retrieve only the positions assigned under an organisation unit and if there exist a specific FM for that or any other evaluation paths which allowed that?.

Thanks.