Hey Bryan,
Officially not no ;-)
However there are a few ways to *maybe* do what you need.
Option 1: Renderview
If your framebuffer contains only one single scene, you could use a Renderview. You can then assign the scene to your Renderview Material and reuse that material in another scene.
Option 2: Loop the output back into the input
If you have multiple layers on your framebuffer, and the framebuffer needs to be on air as well, you could take the output of the FILL + KEY-outputs (or only the fill ofcourse) and send it back in to your videocard on one or more inputs.
However this will bring a delay of at least 4 frames but probably more, depending on the videocard.
Option 3: Use the WindowCapture
I'm not entirely sure if this works, because I have never tried it and it's also not the cleanest solution.
Also, this one would only work if you don't need the output of the framebuffer on air.
You could use a virtual output on a secondary screen. Run your scenes on the virtual output and then use the Window Capture layer in a Material to capture the output of the Virtual Output and then use that material inside your scene.
Downside is that you have to keep this virtual output open on a second screen or other wise the link for the Window Capture gets broken.
Like I said, not the easiest or the cleanest solution but it might work ;-)
Stay safe!
Kenneth
#XPression