I'm perfecting this at the moment, got Mascherano/Busquets sitting just in front of the defence. They're essentially a little triangle with the DMC just in front of the two CBs; the DMC essentially acts like a stopper which gives my attacking wing backs time to track back to become a back four again. Not totally Barcelona-esque, but I think it's about as good as it's gonna get.
This was achieved by setting Masch/Busquets as an Anchor Man, and setting all the sliders to the absolute minimum, and having run with ball, run from deep etc. as rarely. I've got mine on zonal marking with no roaming from position, so I guess he just marks the area in front of the two CBs and doesn't move much. Additionally, it might help if your DMC had the PPMs of 'stays back at all times', 'plays short, simple passes' and 'runs with ball rarely'. Hope some of this helps mate.