It's in "/home//.hedgewars(you will have to press control-h to view this folder in nautilus)/Demos"

Hm. I wonder if our "Associate" button should also try running basically ln -s ~/.hedgewars/Demos ~/Desktop/Demos

Or somesuch.

BTW, for new ubuntu people. If you browse to .hedgewars in nautilus, and middle click on the Demos folder and drag it to your desktop, you will be prompted if you want to link it there. If you link it, that will make a quick shortcut to that folder.

thanks guys, i have found the folder, but...... ITS EMPTY!!! i have pressed ctrl+h but nothing happens, it refresh the folder and its still empty, please help me, i need the replay for youtube

Shouldn't be empty unless a game didn't finish and you only played one game (check saves then)
BTW, you should enable timestamped saves in settings, otherwise it only saves your last game.

in game- i can see the replay

in folder- empty!!!