How do I find a group that's just farming together?

I mean through the noticeboard. I try to join groups, but I can't find anyone else, go through their portal, they leave game, I'm stuck unless I use up a portal scroll or wander around wasting time. Rinse Repeat.

I get this feeling like I'm joining a d2 party after the goal has been accomplished, but the problem seems worse in this game, because you more or less enter a party blindly without any info about how long it's been going, or anything.