When you are in the Accruals page, and inside the Accruals tab, the Batch Post button is located on top of the top left corner of the table with the accruals. Click the button to batch post accruals and the modal below will appear on your screen.
Fill inn the Month/Year field, and Business Unit if wanted. When clicking 'Post' a pop up will appear telling you how many documents will be posted. Press the 'Post' button to complete posting.