Fence height - reference height according to building regulations

Greetings!

I am already planning a bit for our future fence construction, even though there is still quite a bit to do beforehand.

According to the building regulations (State of Saxony-Anhalt), an enclosure up to 2 m in height is exempt from approval. I am planning a double rod mesh fence, but I am now unsure about the reference height from which the height applies. The term "naturally grown ground" was mentioned as a keyword, but that is not entirely clear to me.

For explanation:
Our property is located on a former open-pit mining site. The entire building area was virtually artificially filled and exhibits varying heights.
At the time of purchasing the property, there was a slope – the property suddenly rose steeply in height away from the street. We removed the slope during the construction phase and now practically have a step on the property.
Furthermore, we will need to add some fill "on top" later to reach the final property height.

What would be the reference point here?
Black = Street level, reached at the spot by removal
Green = Current property height, so far without further processing
Brown = (approx.) Later property height after filling

The reference point is, for my understanding, the black line. No matter how your slope is, you have to catch it at street level.