I could offer you the Widget used by myself for the PHoeNiX Preset, @yuuiko in AquaTouch, and (I think) @GoldenChaos in his homonymous preset.
Basically it will display your AirPods' battery levels one above the other, we all got rid of the battery level of the Case (I think though @K2DesignLab has a preset with all three values, I just don't find the link anymore…).
Here is the widget: AirPods Widget.json (63.7 KB)
Here is the trigger: Reset AirPods Widget.json (1.8 KB)
Import both .json files just like you did before (the trigger will appear in the triggers section don't worry if you don't see it the Touch Bar). Hold the widget in the TouchBar and write your AirPods name when asked (important: if you use the standard name like Wao's AirPods don't type it, but paste it from the System Settings → Bluetooth section - for any reason the ' used by apple is some other odd special character we didn't figure out yet).
Last but not least, check in BTT and give the widget the option to connect to your AirPods when hit 
Voilà!
