So if I understand correctly you have added an attribute to the Administration.Account and want to compare this field with another data entity that also has this field CompanyName.
First try never to adjust Marketplace modules because if the module needs an update you will loose all your changes. Secondly it would be wiser to set a reference between the user and that data entity (let's call it Company for now). Third do note that a user has an account not is an account.
So let's say your domain model has an entity employee and an entity company you draw a reference between those two so that a company can have multipe employees. The employee has a one on one reference with account because each employee has only one account.
So it look like this. Now I want to retrieve the company of the current user.
Now you have the company of that user.
Regards,
Ronald
Hi Roy van Buul,
can you share your domain model, so that answer can be more accurate to your model.