I believe it is possible. You can only have one session, but you can monitor multiple ports. For example:
You can monitor switch ports 0/1 and 0/2 using switch 0/24 to actually see the traffic.
monitor session 1 source interface switchport 0/1 both
monitor session 1 source interface switchport 0/2 both
monitor session 1 destination interface switchport 0/24
#show monitor session all
Monitor Session 1
RX Only: None
TX Only: None
Both: swx 0/1, swx 0/2
Destination Port: swx 0/24
You can read more on port mirroring for both CLI and GUI in the following document: Configuring Port Mirroring in AOS
I hope this helps.
Thank you very much it works perfectly.