There was a thread in here where I described what I was trying to build, but it's basically trying to ape 1973 Ajax. The middle CM is Neeskens, so box-to-box, and is supposed to mark the other team's main creative outlet. That's actually why I posted that goal; the guy who scored was the Neeskens role, who would frequently swap positions with Cruyff. I would think the only player capable of this on Barca would be Mascherano in a more defensive way. The outside guys can just be whatever suits them. Ideally the outside forwards are one IF (Johnny Rep) and one Winger (Uh... Piet Keizer I think). At City I used Pato as the winger on the right and Adebayor as the IF on the left. Fullbacks are attacking wingbacks. CF is the best role for your Cryuff, so I'd say either DLF (A or S role, probably depends, but he should be a goal scorer as well as a creator), CF, or T. Tevez was a T I think, but he has good PPMs that cause him to score goals and not just spray passes.
Then there is very high creativity and roaming and almost a max-high defensive line and pressing, offside trap, and sweeper keeper with a super high mentality. It's actually kind of ridiculous how often teams will completely wilt under the pressure and concede possession with clearances almost immediately. The FR and FL really makes the difference here IMO because there is zero space for the fullbacks; and with Tevez at CF, he could basically press both CBs. Tempo is high, but not ridiculously so (Ajax would play a lot of quick long balls into space if the opportunity was on), and I tried to balance this out with high time wasting (so they keep possession, although technically that team didn't really sit back and tiki-taka like Barca unless they were sitting on a lead like against Juventus in the European Cup Final). Finally, I play really wide, just like Ajax did. I find that the 3 CMs allow me to play so wide when otherwise it would cause an FM team to lack possession. The final piece is a central defender who will step into the defensive midfield when my team has the ball, which I don't think is quite possible on FM at this point, except with the "classic" tactics, where it actually is possible, but I prefer the simplicity of the creator.
I actually think the best club for this is Manchester United with maybe Welbeck/Chicharito-Rooney-Nani, and the Fletcher as the BtB. The other candidate of course is City with Aguero/Tevez and Yaya. They don't have the right kind of wide players though, so there would be a lot of wasted talent in the original squad as Silva and Nasri don't quite fit in aside from perhaps side CMs.