— sadly not all at once, however you can instead use a global variable eg: ActiveGroup
and then in each group create an event "System object > compare global variable > "ActiveGroup" = 1" or similar, then throw the events underneath.
This means you just change your variable and whichever group has that number will be active <img src="smileys/smiley1.gif" border="0" align="middle" />
Edit: Also, you might like the examples kit I made for Construct Classic which has a lot of source codes to games and examples I've made. You can grab it from the link in my signature here <img src="smileys/smiley1.gif" border="0" align="middle" /> (it also has a link to the newest version of Construct Classic, Version R2 on Source Forge)