There's a few ways:
1: If you're using a laptop with a trackpad, swipe up with 3 or 4 fingers to display all windows on your current desktop. Select the window you want.
2: Press the button on top of the keyboard with 3 different rectangles of different sizes. This will display all windows on your current desktop as well.
3: On the task bar with the google chrome logo, right click and in the menu and it'll display all windows for you to select.