How can I open the original junction folder?

If I want to open the target junction directly or it's parent, how would i go about that?

Go OPENCONTAINER=target will take you to the parent of the target, and select the target there. You could then push return if you wanted to be in the target itself.

If you want to go directly into the target itself, you can use this:

function OnClick(clickData)
	var selected = clickData.func.sourcetab.selected_dirs;
	if (selected.count == 0) return;
	var path = DOpus.FSUtil.Resolve(selected(0),"j");
	clickData.func.command.RunCommand('Go PATH="' + path + '"');