3 way switch four wires
It looks like the yellow one going to the 3-terminal Wago is the common from the nearby switch, and is supplying switched hot to the lights in the left and right conduit. 

The other two yellows going into 2-terminal Wagos are travelers.  The center conduit brings those, and also neutral, which is the return for the light, and two unrelated oranges that look like an unrelated switch loop. 

Someone might send a memo to this electrician reminding him all those different colors of THHN wire are on his truck for a reason.  Using the same color for common/switched-hot and travelers is kinda confusing.