The Build Manager gives you easy access to crucial output preferences. It is accessed by clicking the Build button in the top toolbar.
The node grid shows you all the nodes marked for export. You can temporarily toggle a node by clicking the checkbox next to the node. This does not affect the build, only the output. This can be useful when you just want to see a few specific outputs, or you need to go back to rebuild an older project for selective output.
When a node has multiple outputs, such as the Erosion and Breaker nodes in this example, you can individually toggle which ports should be saved as files.
For details on how to use the build manager, see Building Terrains