I have asked for a similar feature - sort of like being able to control the camera position and scale during a recording (good for zoom ins, pans, etc). So I don't think it exists.
So what I do is I create a scene for each one. You can crop the audio files just inside Ch (just grab the edges and drag them inwards) - so you can drop the same audio file onto each of the scenes.
What I sometimes do is create a big long scene as the wide view, then overlap shorter scenes on top either in Premier Pro, or by creating a scene from other scenes in Ch itself (you can drag scenes into scenes, and so build up big scenes from a series of shorter scenes).
Note, you could also record at a higher resolution then use Premier Pro to zoom in/out, but I found this more pain than it was worth. Without increasing the resolution, zooming in was blurred.
Note also, there is a "dynamic link" feature where you can drag a scene into Premier Pro or After Effects. You can then do zoom etc keyframing in After Effects. I have not tried this to see if it automatically works out the render resolution to use correctly. For my little laptop, it was just too sluggish to use day to day. I find the fast scrubbing inside Ch to be so useful that I minimize everything I do in other products. But a beefier computer with a good graphics card etc may fare better.
I agree with alank99101739 the easiest way to achieve this for me has been to animate a master scene with all 4 characters. Then duplicate that scene in the project panel (ctrl + D) Once you have a duplicate scene for each character, you can adjust your transform properties to zoom in on each character, and export a close up or medium shot of each character's lines. This is a more exact way to edit, sometimes if you export your master scene into AE or Premiere and zoom on it, it can start to pixelate depending on your settings.
I thought there was a feature request for camera movements - a global X/Y/scale setting applied after everything else, so you can zoom in on one character for a bit, do pans, etc without having to duplicate the scene or pan each character separately. (But I could not find it just now.)
It would not work if you are trying to do a nice perspective pan (foreground and background move at different speeds), but its useful for simple cases. At the moment there is no way to apply scale to draggers for example. That is, you can change Position X/Y and absolute X/Y (before and after Transform/scale), but there is no transform/scale you can apply to draggers. A camera X/Y/scale would be a final global setting applied to everything else, allowing zoom in (including a panning zoom) without having to create a new scene, and without losing screen resolution. I try to do it at present by doing scale and position transforms of each individual puppet in the scene, but its tricky/time consuming to get the positions right.