Mediator variable feedbacks to IV


I am trying to create a mediation model for:

X1=employee capability; X2 (Mediator)=Company (pooled) capability; Y= employee earnings

Although, I am not sure if I can still call it a mediation model when I believe and support that X1 and X2 have reciprocal relation. Where, employee capability (X1) influence the company capability (X2) and vice-versa, then both influence employee earnings(Y). I assume that at some points, one is greater than the other or one relationship may not be there (i.e. a or b).

But my objective is still to establish that company capability mediates the employee capability - employee earnings relationship. It's just that some literature tells me that company capability also matters to advance employee capability. So in the end, both capabilities explain employee earnings.

Is this considered a usual mediation model? How do I model these four relationships instead of three?