I wonder if it is possible to listen two frequencies VHF at the same time. Example: radio operator panel on the left side (VHF1) Com1 on Unicom 122.800 and radio operator panel on the right-hand side, (VHF2) Com2 on a Atis frequency.

Yes it possible It's even possible to listen the two frequencies from the same Radio Communication Panel (RCP), push VHF 1 to tune VHF 1 and then push VHF 2 to tune VHF 2. If you push the the VHF 2 on the capt RCP the light between the ACTIVE and STANBY window will illuminate. Then go to the Audio Control Panel to select both VHF 1 and VHF 2 audio selection.

it is right what I sought. Thank you very much for your answer