When you receive two or more than two debit notes against a single purchase invoice you need to follow the give procedure:

• Go to Purchase Invoice List and Open the respective purchase Invoice for which you need to create a debit note.

Refer Article: How to create Debit Note for a raised Invoice.

Here you will be able to make a single Debit Note for the purchase Invoice.

• Now, to record another debit note, you need to create a Standalone Debit Note 

Refer Article: How to create a Standalone Debit Note

• Once you create a Standalone Debit Note, you need to knock off the purchase Invoice against that Debit Note.

You can do that by passing a Journal Entry as explained in the steps below:

• On the dashboard search for Journal Entry List in the Universal Search bar

You will be able to see list view of the Journal Entries

• Click on " New" (as shown in figure) to pass a new entry

Following journal entry details page will open up:

You need to fill up the following details:

• Entry Type:Select it as Journal Entry from the drop-down
• Series: Auto generated on basis of previous recordings
• My Branch: Your company branch from whee you are raising this transaction
• Posting Date:Date on which you want to record this transaction in your accounting books
• Company: Your company name will be auto-filled

Now pass the Journal Entry in the following manner;

• Account: Pass the dual entry for creditors account 
• Party: Will be auto filled on the basis of reference of Invoice that you enter to knock off
• Debit/ Credit: Will be auto-filled on the basis of reference of invoice knocked off

To knock of the Invoice you need to enter the Reference of the purchase Invoice:

In the Reference section you need to enter the following details:

• Reference Type: Select Purchase Invoice from the list of various option
• Reference Name:  Purchase Invoice Number Against which this debit note is to be knocked off
• User Remark: You can enter the remarks. detail that you want to in this section

Click on "Save" and "Submit"