Solved this issue by unsing Information Sources Customer Invoice and Supplier Invoices. You can fetch the open balance data from those sources. 

You need to create an open balance snap shot first. 

In order to do that you need a history category.

Aurena:

1. Open page “Customer Open Balances History Category”
   Path: Financials>>Payment Basic Data>>General Payment>>Customer Open Balances History Category
2. Create a new record by using the plus button in the header frame.
3. Define your individual Id.
4. Save.
5. Create a new record in the lower frame called “Open Balances History Companies”
6. Apply one or more company ids which should be connected to the corresponding history id.
7. After you saved the records open window “Customer Open Balance History”
   Path: Financials>>Accounts Receivable>>AR Analysis>>Customer Open Balance History
8. Select you currently created history category.
9. Create a new record by clicking on the plus button.
10. Select a date as the cut-off date.
11. Save.
12. Use the command button on the created record and choose “Details” from the context menu.
13. You can now see the open balances with reference to your applied cut-off date.
14. This data is now available for the Business Reporter in particular for the information source “Customer Open Balance (FACT_CUSTOMER_OPEN_BALANCE)”.
    → it works similar for Supplier Open Balance.

You can also schedule the creation of the open balance histories.

Best regards

Benjamin Kempe