I found this related question, but that's not quite it
Is it possible to model this with integer programming:
$$A = \begin{cases} 1 & \text{if } B \geq C \geq D \\ 0 & \text{otherwise}\end{cases}$$
where $A \in \{0,1\}$, $B, D \in \mathbb R$ and $C \in \mathbb N$. We have upper and lower bounds on $B$, $C$ and $D$.
Thanks MrHug, I should have thought of this myself after your first hint.
after using the solution from here twice with the resulting binaries $A_1$ and $A_2$ we can form another problem: $$A = \begin{cases} 1 & \text{if } A_1+A_2 \geq 2 \\ 0 & \text{otherwise}\end{cases}$$
This one can be solved with a little hint from there:
$$A_1 + A_2 \geq 2 - M * (1-A) \\ 2 - \epsilon \geq A_1 + A_2 - M * A$$
where $M$ is a big value and $\epsilon$ is a very small value (above 0, below 1).
It's a bit unfortunate that so many variables are needed as $A$, $A_1$ and $A_2$ are cubic in my case. But I'm glad about this solution.