In Fusion, you can use shortcuts to operate a single-button mouse as a two-button or three-button mouse.
The defaults are Control + primary button to mimic the secondary mouse button (right-click) and + primary button to mimic a third button.
You can change the shortcut.
Select VMware Fusion > Preferences and click Keyboard & Mouse.
Click Mouse Shortcuts to go to the Mouse Shortcuts pane.
Double-click the mouse shortcut and hold down the keys for the new shortcut.
To restore the defaults, click Restore Defaults.