This short blog article outlines how to search for the internal value of an option field.
The selectable options from option fields always consist of two values, a display value and an internal value.
Option 1: Build the desired filter in the advanced find in Dynamics 365 and download the fetchXML. You will now see the internal value, highlighted in red as you can see in the figure below - Active=0
Option 2: Navigate to Dynamics 365 > Settings > Customization and select Customize the System > [Your Entity] > Fields > [Your Field]
You can take a look at the properties of this field there and check the internal and display values of all available options.