VMWare Fusion and moving between monitors
With the help of Autofit command of view menu you can resize the guest display resolution. There are four commands listed below:


Fit Guest Now - Guest operating system display size to match current Workstation console.
Fit Window Now - The Workstation console to match the current display size of the guest operating system.
Autofit Window - Workstation console to maintain the size of the virtual machine's display resolution.
Autofit Guest - Virtual machine to resize the guest display resolution to match the size of the Workstation console.


As per your requirement, Fit Guest Now command will remain the best.

You should also refer this: https://www.vmware.com/support/ws5/doc/ws_running_display_fitting_host.html