Here, 3-tier design were like this:

3 tier architecture

The MVC pattern would be:

Model View Control

Meaning that:

1. In the 3-tier equivalent, communication between layers is bi-directional and always passes through the Middle tier

2. In the MVC equivalent the communication is in unidirectional; we could say that each "layer" is updated by the one at the left and, in turn, updates the one at the right –where "left" and "right" are merely illustrative

P.S. Client would be the View and Middle the Controller