Assign Business Partner to T_Code Authorization

Hello Everyone,

I have created a business Partner with a person xyz and have assigned particular responsiblities to this person xyz as to only have access to a particular company code and so on . Now can anyone of you suggest me how can I link this BP to authorization as this person xyz should only have authorization to transaction MM02 and MM03 and not to MM01.

Please help me to link a Business Partner to Autorization of a transaction code.

Thanks in advance.