The Devicetree Visual Editor lists all available nodes for the selected devicetree file in a hierarchical Nodes View.
The Nodes View displays the nodes of the devicetree file for the application and the application context displayed in the View header (hello_world_3 and build, respectively, on the image above).
All changes to nodes and pins here are automatically mirrored in the code of the active devicetree file (shown in the Build Contexts View header). The changes are also applied in the graphical Peripherals and Pins Views, which let you inspect and modify node properties and pin assignments.