This should work:
> Door overlapping Ground
System-> Pick 0th Ground instance : Door Set room1=Ground.room
System-> Pick 1th Ground instance : Door Set room2=Ground.room
You can also use Ground.pickedCount expression to check how many Ground instances are picked in this event.
Thanks again dop2000
Ooooh, pick nth instance! Shit I miss that sonofabitch ^^
But it didn't work right yet, all doors are getting room1=0 and room2=1 as if I was picking the two first grounds of the layout and not the two ones the door overlaps. And yes, they are as a subevent of Door overlapping Ground.
I tried picking both ground separately by lowest and highest 'room', same problem. It seems to ignore the 'Door is overlapping Flor' event and pick only two rooms at all.
Tried making For Each Ground and Door events to pick then all but non works. :s