Hi Nuvan,
If i understood correctly, You have added the attribute in Tree node. As sigrid suggested SDN links i believe you have added get_XX and GET_P_XX in XXX_CN02 and XXX_CN03 method.
Also in table _line method you must have declared your field.
You might have below issues:
1. spelling mistake in attribute name declaration for parent and child node.
2. Parameter declaration could be missing in methods.
3. Chosen the wrong configuration key.
Check if not above. Do share your issue in more detail.
Regards,
Atul