Is this a controller based setup, or using Instant mode for the 277s? I'm assuming controller based because of the forum this thread was posted in, but should validate that assumption.
I'm not sure whether your main site is at the top or bottom of the diagram, but if you number your APs sequentially from top to bottom:
AP1 - top AP, presumed wired to the main site
AP2 - first poll mounted AP
AP3 - second poll mounted AP
AP4 - bottom AP, presumed wired to the remote site switch
APs 1 and 3 in this scenario would be configured as mesh portals. From their perspective, they have wired uplinks for connecting back to the controller.
APs 2 and 4 are mesh points. Their uplink to the controller is over wireless, via the portals above.
The mesh points (AP2/AP4) would be in an AP groups configured with ethernet port profiles to bridge (or tunnel, depending on your need) across the wireless. This enables AP2 to provide AP3 with a wired connection as though it was connected to the same switch as AP1. Similarly, AP4 then provides a wired pass through to the 3560 as though the cable were directly connected to the same switch as AP1.
Use two mesh profiles to force the hop across the light pole (AP2 only talks to AP1 via mesh1, and AP4 only talks to AP3 via mesh2).