Ensure your Google apps are up to date as the following steps apply to the most recent version.
From the Map Tray screen, tap the Dropdown menu next to the desired field (1, 2, 3, 4), configure as preferred then tap Done.
From the Navigation View prompt, select an option:
From the Night Mode prompt, select an option:
From the Night Mode Brightness prompt, slide the dot left or right then tap OK.