I do not have any code or examples or know where to find any.
You will need to add custom JavaScript to ACF. You will need to alter the AJAX data by getting the value of the taxonomy field and adding it to the data. Then you will need to use that added data in the filter.
On top of this you will need to figure out how to trigger ACF to refresh that list if the term selected in the taxonomy field is changed. I haven’t got a clue were to start for this. This would probably be the hardest part and I have never seen where anyone has accomplished it.
If I had to do this I would use 2 dynamically populated select fields and do most of the coding for those fields myself, for instance using the values in the fields to get the correct terms/post. There is a basic example of doing this for posts here that would take some modification to use terms. https://github.com/Hube2/acf-dynamic-ajax-select-example/tree/master/dynamic-select-example
