This article is applicable when creating and posting a credit invoice directly from an invoice described here: Credit invoice
When posting a credit invoice you can choose to match the receivables for the two invoice this will eliminate the issue of having two open amounts in receivables report.
The functionality is enabled under Settings > Invoices > Invoice Settings > "Enable payment matching of debit invoice when posting credit"
Directly when selecting "Post" on the credit invoice you get a dialog asking you if you want to match the two invoices (original invoice and newly created credit).
Technically the balancing creates two payments (of the same amount, one positive and one negative) and post it to each of the original invoice and the credit invoice. In the dialog you can chose what account to use for the balancing, there will be a debit and credit posting on the same amount on the financial account in the end.
Walkthrough of full flow of crediting an invoice and match the receivables:
Original invoice which has posted €125 to A/R account (example 1510). There are no payments to the invoice.
Create a credit for this invoice:
A credit is created, select "Post":
Confirm to balance the balance the receivables for the original debit invoice and the new credit invoice.
After this, both the original invoice and the credit invoice have status settled and receivables is 0.