How to toggle 2GPIO's with 1 command?

How can I activate 2 GPIO’s using 1 switch?

Thanks in advance!

I suppose you might use a rule

rule "copier"
when
   Item someSwitch received command
then
   otherSwitch.sendCommand(receivedCommand)
end

Please explain why. If this is to avoid invalid electrical states like say to enable both directions of a rollershutter at the same time in order not to destroy your motor, then you shouldn’t rely on this to work in software.
In other words: this is a bad idea to save just a little money, get proper electrical circuits/actuators that take care of this instead.

Or use a proxy switch with a rule to activate both GPIO’s. This way allows you to still be able to activate a single GPIO if needed.