If the remote computer has more than one monitor, additional buttons will appear in the toolbar.
Note: Support for Multiple Monitors is available even when using ISL Light to tunnel a RDP connection. Please refer to this article: Create RDP/SSH session (Step 3).
Video Tutorial
Open Monitor in New Window
Step 1

Click the "Open Monitors in Separate Windows" button in the View Menu.
Step 2

Each monitor has its own window. You may drag&drop application, files or folders across two windows.
To switch back to single window click the "Close Other Windows button or "All Monitors/Desktop" button.
Show Monitor 1

Click "Monitor 1" button from toolbar to set view region on monitor 1.
Show Monitor 2

Click "Monitor 2" button from toolbar to set view Region on monitor 2.
Show All Monitors

Click "All Monitors" button from toolbar to view both monitors at once in a single window.