Follow the below steps for attaching a disbursement onto a bill:
Go into DPS OneOffice and click on Client Postings.
Select Bills.
Type in the Matter Ref for the matter you intend to post to.
Select the Select Disbs button.
This will bring up a popup, right click on the line of disbursement you want to attach and select Select.
At the end of the row you will notice the Sel column will change from NO to OK on the row you have changed.
Select OK.
If you are ready to post the bill, select Post on the bottom right of your screen.