Press [command][control] simultaneously.
Prior to Fusion 5, this combination worked. However, it does not work anymore with the latest version.
That may be because you haven't told Fusion to use the paired Bluetooth devices, from the Devices menu. Once you do that, all should be well again.I just found something interesting.
Control+Command works when I use the keyboard on my rMBP. However, the combination does not work when I use the Apple Wireless Keyboard.
Anybody knows that is going on?