Thank you for the KB-Post. I'm very much afraid we do not have any native sensors to monitor AD group memberships in PRTG, nor are there any planned for the time being.
Please bear in mind, as with all things customising, which includes script sensors, customizing on pages in PRTG (reports, map objects, etc.), users are on their own. This has to be done by the user. While we do have a few explanations and rough guides in our KB for that, as well as the API-Documentation, be aware, that it's only supposed to work as a base, and using it is at your own risk. To help with custom scripts as sensors, I encourage you to use the API documentation in PRTG. The script should return the values to PRTG in the expected format (see your own PRTG under "Setup">"PRTG API">"Custom Sensors"). Also follow the manual (https://www.paessler.com/manuals/prtg/exe_script_sensor.htm) and feel free to search the KB (https://kb.paessler.com), for a few examples on script sensors.
Try using the following script as a starting point:
Perhaps other users have suggestions too.