...Into an Access Database. For example, X company purchases products from the G10, S20, S35, S40, S30, O50, AND O70 product groups. Is there a way to incorporate this extra information into a the database?
Without seeing the table structures is is hard to know for sure.
I would assume that you have a "product list" table. To this table you would add a way to track with group or groups a product is a part of. If a product can only be in one group, simple add a field. If a product can be in multiple groups,you will need a child table (one to many relationships) .Then you can create a query to get what you want.