Here's the problem I'm looking at:

$F$ is a perverse sheaf (or a regular holonomic D-module, or even a mixed hodge module) on $\mathbb{C}^2$ stratified by $z_1 = 0$, $z_2=0$. It can be caracterized by a quiver $$ \begin{array}{ccc} \psi_{z_1}\psi_{z_2}(F) & \leftrightarrows & \psi_{z_1}\phi_{z_2}(F) \cr \uparrow \downarrow & & \uparrow \downarrow \cr \phi_{z_1}\psi_{z_2}(F) & \leftrightarrows & \phi_{z_1}\phi_{z_2}(F) \end{array} $$
where arrows are the canonical and variation maps.

Consider $f(z_1,z_2) = z_1+z_2$ (or any curve passing through $(0,0)$ transverse to the axises).

How can we compute $$ can: \psi_f(F) \leftrightarrows \phi_f(F) : var $$ in terms of these data?