Is this a bidirectional buck/boost converter
I don't understand if it, or its development board, can both boost input voltage to output and buck output voltage back to input.


LT8705 is the IC and using LT8705 is the evaluation board/development board is DC1924.
It can work as both boost and buck converter and can generate output voltage above, equal to or below the input voltage.
                                


  Power Control Switch


Datsheet shows a simplified diagram of how the four power switches are connected to the inductor, VIN, VOUT and ground. Figure also shows the regions of operation for the LT8705 as a function of VOUT -VIN or switch duty cycle DC. The power switches are properly controlled so the transfer between modes is continuous.