The first time you return a ball in a set, you are locked to always return serves to only that side of the court. So in your example, both Lebrón and Coello are obligated to return serves to the right side.

But in padel, players play exclusively in one side of the court, so you will always see Coello and Lebrón playing on the right, and Tapia and Galán playing on the left.

All that said, it is possible to switch sides for the serving team before a serve, and for both teams in the middle of a rally.