The web client isn't the best, so when I had to setup a few wireshark monitors for VMs I went looking for PowerCLI solutions. I came across some code from LucD and put them into functions.
https://communities.vmware.com/message/2507811#2507811
https://communities.vmware.com/message/2648926#2648926
Add-VMwareMirrorPortForward -MirrorSessionName "SessionName" -MirrorDesc "Description or Reason for Mirror" -WireSharkIP "192.168.1.10" -vmName "VM_Name" -dvsName "DVS_Name"
Remove-VMwareMirrorPortForward -mirrowSessionName "SessionName" -dvsName "DVS_Name"