Enable Cross Hairs using Final Cut ProX 10.5.2

I have upgraded to Final Cut Pro 10.5.2 I want to enable cross hairs on the viewer. I want a talking head on one third of the screen and different video on the rest of the screen. With cross hairs enabled I have been able to drag the video to where I want it.

How do I enable cross hairs, or if that is no longer possible with 10.5.2 how can I achieve what I want to.

I'm using a MacBook pro 2015 and Big Sur.