You can easily hide the user interface (UI) for Google Maps desktop by going into the full-screen mode. To enable full-screen mode, simply click on the button with the four arrows located in the upper-right corner of the map.
Alternatively, you can also hide certain elements of the UI, such as the search bar, by using keyboard shortcuts. To do this, simply press the "Ctrl" and "Shift" keys at the same time, and then click or drag your mouse to select the area that you want to hide. Once you have selected the area, the selected elements, such as the search bar, will disappear.
Moreover, you can also customize your Google Maps settings to hide certain UI elements permanently. To do this, click on the menu button (three horizontal lines) located in the top-left corner of the map, and then select "Settings". In the Settings menu, scroll down to the "Map view" section and uncheck the boxes for the UI elements that you want to hide, such as the scale bar or zoom buttons.
In summary, there are several ways to hide the UI for Google Maps desktop, including enabling full-screen mode, using keyboard shortcuts, or customizing your map settings. Try out each of these options and see which one works best for your needs.