When you take a look at the Automap for the first time you will see the complete tree, including all your hosts. If you only like to see one part of the tree you have to change the following configuration setting:
Defaultroot tells Nagvis what host to start your tree with.
Example of how the defaultroot works in NagVis Automap
In this example we have the following tree in OP5 Monitor.
Here the demo host is set to defaultroot and all of its children are displayed. If you set the host switch1-gbg as defaultroot in Nagvis the automap only display switch1-gbg and it's children (environment-gbg and printer-gbg). The picture below shows how it would look like:
This is done when you have one of the maps in Edit mode. There is no Edit mode on the automap so these steps have to be done on another map.