Very unlikely to be possible as Unity View relies on the fact that the all the processes related to the VM are running locally on the Mac host versus VM running on an ESXi is running within that ESXi (even though that ESXi might itself be a VM running on the same Mac host). If you noticed on the Activity Monitor that there are extra processes created when a Fusion VM is switched to running Unity mode. It has been a while since I used Unity view, but I think even some of the Windows apps running in the VM would have an some entry within macOS Activity Monitor.
Secondly, the view to an ESXi from Fusion is very similar to a VNC session so effectively it is just a graphical terminal view.
