Question about data source 2LIS_03_BF

Hi Experts,

I'm trying to load data about material movement information and using this SAP standard datasource 2LIS_03_BF.

But what's the problem is that after I extract data from R I found data fields for puchase order(EBELN) and item(EBELP) are empty, do you know why? and how can I get data about these two fields?

Thank you.