As of version 2025.b, Open BIM Quantities can use variables in the “References” of the items, in a similar way to other fields such as the “Detail line“ and “Tags“.
When changing the reference of the items, it is important to note that the codes must also be different.
Open BIM Quantities will automatically manage this when using “Update the quantities“ in the “Bill of quantities“ tab. The ‘Code’ indicated for the “Item“ in the “Rule of measurement“ will be used as the base code, adding a suffix for each different reference.