PO created with ref to PR

Hello

In our scenario, one person has created the PR with his ID and put his PUr Group in PR,

with respect to PR one more person created the PO, but Pur group taking from PR, this is correct also as per SAP Std.

But user told me that, when he is created the PO with Ref to somebody's created PR then it would not take the pur Grp from PR, it will take the his Pur group, automaticaly

how is it possible. if possible give some guidence.

regards

sapman