How do I view a listing from two different MLS organizations when I belong to both?

You can view a listing with both your primary and your secondary MLS. Be sure to choose and set your primary MLS in your profile. Listings from this MLS will show up by default. You can access a secondary listing by clicking on a link to the other listing in the right sidebar of the Property Details page. When a property is listed with more than one MLS, you will see the additional listings in that sidebar.