Option 1 - Post the deferral in GL. Then click on Transactions, point to Financial, point to Analytical Accounting, and click on Edit Analysis. Select the Journal Entry of the deferral and proceed to add/edit the AA data.
Option 2 - Stop the batch in GL and add the AA codes to the transactions in the GL work batch.
Option 3 - Enter default AA codes in the Trx Dimension Code Default fields on the Accounting Class, and these codes will get automatically assigned to the deferral entries. However, you would still have to use one of the other options if you want to change any of the codes.