1) first let me know one thing do you need service PO's or material PO's or both
if you want to find individual wise service /material then follow below
Pass order(NPLNR)/W.B.S.E(PS_PSP_PNR) in EBKN get BANFN & BNFPO pass this in EKPO here you will get the details with material code for service PO's package number (PACKNO) will be updated by using this go to ESLL pass package number(PACKNO) and take package (SUB_PACKNO) and pass in package number(PACKNO) you will get the service items for that PO
Regards
Ambarish