It is realistic but a bit difficult but I think Barcelona's main target right now is La Liga and it is quite possible because they are at the top of the standings now and their performance is quite impressive and also consistent.
Barcelona's squad this season is quite even in all lines and related to the productivity of Barcelona's front line, it cannot be separated from the improvements they made to be better than last season and the most highlighted is the contribution of their young player Lamian Yamal who played very well this season but it also cannot be separated from the encouragement and also the strong chemistry between Barcelona players as a whole.
I don't think Barcelona is only targeting La Liga. I see barcelona giving the same effort in every match of La Liga, Copa DelRey and champions league. Hansi Flick is interested in winning all three titles. Flick's target is not just securing La Liga.
Barcelona is now in a somewhat safe zone in La Liga. The top spot of the table is occupied by Barcelona. Even if they lose a match, the top spot of the table will be occupied by barcelona. Even then, if Barcelona cannot maintain its performance stability , then they will not be able to retain the top spot of the table. Real madrid is continuing to try to regain the top spot of the table. Only if Barcelona's performance is irregular, we will see Real Madrid at the top of the table..
It's all coaches dream to win a Tribble, but it isn't as easy as winning just one trophy. Barcelona needs to work hard and luck needs to be in their favor for thier dreams to come true this season. None of the competition is sure for them. Barcelona only has a upper hand of winning Laliga, and the other two is a 50-50 chance.