Hi
First load - PCTR then PCTRH then PCTRG - here you have 2 options i.e 2 different layout. In NWBC when you select Profit center group you need to select attribute and hierarchy. When you select attribute its group details. When you select hierarchy then you have to use the assignment file.
PCTRACC is the entity type used to assign company codes to Profit center and this is last activity.
Kiran