Oftentimes when couples have come to an agreement regarding how they want to handle their divorce, they want to use the same attorney to do all the paperwork. You can use the same attorney to to finalize the divorce. However, you could not use the same attorney to represent you both. Technically, when you file for divorce against your spouse, you're suing them. So you all are going against one another and the attorney that you use can only give legal advice to one of the parties.
So if you do decide that you want to just use one attorney, I'll always advise that the spouse who is not receiving the legal advice go and confer with another attorney to ensure all of their rights are protected.