AZ divorce law, divorce litigation right to subpoena financial records

First you must file an action. Then you must get a subpeona. Since it sounds like you are appearing "Pro Se" (without an attorney) you will more than likely have to get the subpeona issued by a judge, as you do not have the right in most states to issue a judicial subpeona (that is a right reserved to Licensed Attorneys and in some states Notary Publics)
Check with the clerk in the court house you file your action in to see what he says is the rule in your home state.

Good luck.

You could also file a motion to continue the current trial and file a motion for contempt if you believe that your soon-to-be ex has failed to comply with the disclosure requirements of Rule 49 of Arizona Rules of Family Law Procedure.

If both motions are denied, bring up the issue at court and request that all after-discovered assets be awarded to you as a penalty for her concealment.