For Fe-I atoms: it stabs the orange atom Fe-II, then the dark blue atom N, and it leaves the unit cell in the proximal orange atom Fe-II. With respect to Fe-I it is a 4-fold rotation axis.
For Fe-II atoms: start in one of the corners of the cube and run the axis through two Fe-I red atoms. With respect to Fe-II it is a 2-fold rotation axis.