If you have been married before, your celebrant will need to sight proof that your previous marriage has ended before you can be married again.
You probably received a divorce certificate at the time of your divorce, but where is it now?
If you need to obtain another divorce certificate, this cannot be done at the Registry of Births, Deaths, and Marriages. BDM only register births, deaths, and marriages. Not divorces. The court system registers divorces.
In Australia, you can apply for your divorce certificate online. An electronic document is able to be downloaded from the Commonwealth Courts Portal. Here are some links that may assist you:
http://www.federalcircuitcourt.gov.au/wps/wcm/connect/fccweb/how-do-i/divorce/proof-of-divorce/fcc-proof-divorce
https://www.comcourts.gov.au/pip/individual/new
Once you have shown the divorce order to your celebrant, you will be eligible to go ahead with your marriage (providing the other criteria have been met).
