Relationships

I am attempting to create an Access database of my Chart of Accounts.

Each record is uniquely identified by two primary keys: Account code and the Business Unit to which it belongs. So, one account code can be in multiple business units.

However, there are many other fields such as whether an account is open or closed, whether it is a balance sheet code, p&l, memo, trading etc.

I wish to be able to design the db in such a way that I can close accounts across a range of business units and create new accounts that will be applied across all business units but I'm struggling to design it efficiently and to determine the relationships between tables.