Dembele has made a big improvement since his new contract with Barcelona. He has always been criticized due to being very selfish. This was one of the reasons he couldn't show his talent very well in his previous contract times. But now he is more helpful for his teammates. His statistics in the La Liga can be shown as a proof for this actually - 4 goals and 5 assists. On the other hand I must admit that he is still having some selfish matches sometimes. It is like in his nature to try to do all the work from creating a goal opportunity to ending it.
But as long as he keeps this selfish behavior as low as possible he wouldn't have much problem with Xavi. Because Xavi is caring about the team effort very much. He doesn't want to see only one man trying to carry the match.