ADDING SAME ATTRIBUTES ON TWO DIFFERENT ENTITY IN SAP MDG

Hi Experts , I want add same attributes in two different entites how?

I had created a custom data model called ZB and created two entites MARA(type1) and MARC(type4). The attribute BESKZ(Type3) was created and Maintained realationship REFERENCING(0:N) both MARA , MARC, While maintaining the relationship to MARA i'm getting error.

Is that right way i followed? if not, please suggest me right way.