Objects you create using CDO and those CDO recognizes in an onboarded device's configuration are displayed on the Objects page. They are labeled with their object type. This allows you to filter by object type to quickly find the object you are looking for.
When you select a network object on the Objects page, you see the object's values in the Details pane. The Relationships panel shows you if the object is used in a policy and on what device the object is stored.
When you click on a network group you see the contents of that group. The network group is a conglomerate of all the values given to it by the network objects.