Humans are exposed to the environment in a continuous flow of experiences, and the brain naturally divides these experiences into discrete parts in order to interpret and organize them. A model for such a partitioning process has been specialized in Event Segmentation Theory (EST) (Zacks et al., 2009, J. Exp. Psychol., https://doi.org/10.1037/a0015305). Despite the number of studies on this topic, the electrophysiological brain mechanisms that underpin this segmentation process and how it changes during years of maturation, which can be tracked using high temporal resolution technologies such as EEG, are still poorly understood. In the work presented, healthy adults and adolescents performed an event segmentation paradigm, i.e., they watched a narrative video and were asked to divide it into meaningful segments while EEG was recorded. The findings show the relevance to event segmentation of oscillatory activity in various frequency bands originating in different brain areas along with their interrelations by utilizing EEG analysis methodologies such as beamforming approaches. The research reveals a mechanistic chain of different cognitive processes that explains how the brain partitions and structures natural scenes while integrating current models of the situation, perception, and previous experience, as well as how these elements may be influenced by developmental factors.