Getting the Champions League title is not as easy as other domestic leagues, the Champions League is a collection of great teams all over Europe so it will not be easy for Barcelona to achieve that dream even though they have brought their team to a great performance.
The Champions League has a different sensation and the mentality of coaches and players is still influential if they do not have deep experience in the UCL, I believe Barcelona this time will be better to go to UCL even though the previous season could only stop at the group stage.
Every coach's dream is to win UCL. For this, the economic strength of the team is also very important. Not every team, only one team can achieve this. Last year, Manchester City looked like an excellent team and they won the UCL. It's been a great season for Pep and we can see similar things happen this year. They will have tough opponents and UCL will again be the most watched tournament.
Strong clubs in the Champions League on average have a strong economy that supports teams to bring in quality players, it is easier for coaches to bring in the players they want because of strong economic support. Manchester City have proven that their economic power is able to improve the quality of the team by bringing in classy players. Guardiola's effect was also very influential in Manchester City's success last season, he who has experience winning the UCL trophy with Barcelona was able to develop the players that Manchester City has to achieve historic success for the club. This season there will be more tough opponents in the UCL, Manchester City will have difficulty defending the UCL trophy if they are not consistent in maintaining the quality of their games.