Leverkusen is showing a pretty good performance at the moment in the Bundesliga, but on the contrary the first defeat of the season they got in the Europa League against a team that has never been the favorite to win the Europa League, the defeat to Atlanta of course indicates that the mentality possessed by Leverkusen is not enough to compete in the current European competition, this season Leverkusen failed in Europe after the lack of mentality they have so that our doubts arise To be able to see them go far in the Champions League next season, as you said, of course at the moment Leverkusen still needs to improve the quality of the squad they have to maintain their Bundesliga champion status and also compete in the Champions League next season.
Currently it is reported that some Leverkusen players are starting to be approached by big European teams, so if Leverkusen loses some of their main players this season, of course it will be very risky for Leverkusen, in addition to having to maintain the current squad, of course Leverkusen must bring in several other players who are able to improve their mentality and performance next season, I personally see if maybe Leverkusen is still able to compete in the top 4 of the Bundesliga next season, but competing for the title again certainly seems impossible because currently Bayern Munich is starting to improve their squad.
The fact that Bayern Leverkusen were undefeated until the final of the competition shows that they are very strong. However, a team that competes for a full season and is still beaten till the final is not a weak team, and that doesn’t mean they won’t perform as we are saying in the champions league.
I believe they can do it even in the champions league competition, even if they will perform the same as they are doing in the Bundesliga, because I know the Champions League has many more strong teams than the Bundesliga that Leverkusen have already used to, so the thing here is that Leverkusen will not be beaten in the champions league, but with their current status of performance, I believe even if they don't top the table, they will nearly make it to the top.
A club sometimes has its own goals, for example, Bayern Munich, which last season was overtaken by Leverkusen, but Bayern Munich prioritizes matches in the Champions League, even though they only reached the semi-finals, but that is proof that a club that has lost in the Bundesliga doesn't necessarily look weak like that what you said and I agree with all of this.
Not being able to occupy 1st position in the points table is not a big problem as long as Leverkusen can perform well in the Champions League as I said above and it is very natural that a club like Leverkusen, which managed to win the title last season, is more enthusiastic about being able to win a higher title, but it must giving up a little position in the domestic league.
Leverkusen I am sure that this club can show its strongest performance in the Champions League as long as it doesn't make many changes to the players, but I am a little doubtful that in the future Xabi Alonso will also prioritize the Bundesliga title and in the end its performance in the Champions League will be slightly affected.