Complex sentence: In 2015, Etxeberria moved to the first team under manager Ernesto Valverde, and in 2016 he switched to become head coach at affiliated club CD Basconia, controlling a group of players he had previously managed at the "Juvenil" age group level.
Split into simpler sentences: In 2015, Etxeberria moved to the first team under manager Ernesto Valverde. The following year he switched to become head coach at affiliated club CD Basconia, controlling a group of players he had previously managed at the "Juvenil" age group level.