Hi Vengal,
I would say that the source data will be the regular CO-PA data, maybe enhanced with Retail specific fields. The standard procedure is to generate a custom DataSource.
Go to the BW IMG: t/code SBIW.
Follow menu path: Setting for Application-Specific DataSources (PI) > Profitability Analysis > Create Transaction Data DataSource.
Here you can click on the various Help icons next to the menu nodes to get on-line help.
In the end you are able to generate a CO-PA DataSource which starts with 1CO_PA.
Best regards,
Sander