In previous versions of WWT it was possible to define telescope and camera parameters in the instruments.xml file and display the corresponding field of view for the available instrument configurations under the View tab.
The instruments.xml can still be found on my Windows machine in C:\Users\USERNAME\AppData\Local\Microsoft\WorldWideTelescope\data, but I no longer see a way to display field of view indicators. Has this function been removed from WWT?
Never mind, it looks like it was moved into the “Layers” panel. You can click “field of view indicators” as a layer and right click to activate specific FOVs.