The Secret World's site has been updated with a new article to detail the group finder tool that will arrive when "Issue 2: Digging Deeper" goes live on September 11th. The tool will allow players to group for any playfield or dungeon in the game.
You find the tool in your Menu or by clicking Shift + C. Here you can either browse and look for other people who want to do the same thing as yourself, or you can sign up and show yourself as available for the content you want to play.
When signing up you choose the playfield or dungeon you would like to play in, which difficulty you would like and which role you can fill in the group.
Read the full article on The Secret World's site.