It is undeniable fact, indeed Barcelona performance improvement when it was take over by Xavi their having a good progress, but when Xavi plays against big clubs outside La Liga, he doesn't have perfect tactics. Today also in a friendly match against Arsenal, Xavi lost tactically although it was a friendly match but Barcelona shouldn't lose. But anyway I shouldn't underestimate him, Xavi might be able to make a surprise in the UCL later because now the Barcelona squad have a new better players.
Losing to Arsenal was not supposed to happen, not after adding some crucial players to the team this summer. Furthermore, there are certain good numbers of targets ought to be reached this season. Xavi Hernandez will restrategize and implement new game structure, because the blaugrana becomes very weak towards elite clubs outside their league. Barca always dominate games within La Liga but are not giving the same energy in other top competitions, that's their weakness, comparable to PSG in Ligue One.
Their ultimate target is the UCL title, I doubt if they will make it to the knockout stages this time.
I don't think Barcelona main target is to get the Champions League title, it's a ridiculous target if it's true. Because anyway, the capacity that Xavi has until now still cannot achieve that title. Instead of targeting the Champions League title, it seems like it would be better for Xavi to build a squad with better performance. I think it's funny if Barcelona targets the highest trophy in Europe, because the reality is that competing teams have the capacity and quality that is certainly better. So for me, it makes no sense for Barcelona to have such a target.