## 2 Methodology for Selection of Studies
### Screening of the Identified Studies  
The screening phase served to refine the initial dataset obtained during the identification stage, ensuring that only studies meeting the strict inclusion criteria were retained for further evaluation. This process involved a systematic review of titles and abstracts to assess each record's relevance and alignment with the research objectives. The inclusion criteria applied during this stage were as follows:  
1. Publication Year: Studies published between 2014 and 2024 were included, capturing advancements over the past decade while maintaining a focus on recent developments. This time frame provided a balanced view of contemporary research trends and innovations in the field. 2. Document Type: Only original research articles published in peer-reviewed journals or presented at conferences were considered. Works such as review articles, editorials, letters, opinion pieces, policy briefs, and other non-empirical contributions were excluded. This criterion ensured the inclusion of studies offering novel insights, experimental findings, or robust analytical frameworks directly relevant to the research objectives. Language: Articles written in English were selected, reflecting the predominant language of international scientific discourse. This approach enhanced the comparability of studies and ensured a broad representation of globally recognized research. * Full-Text Availability: Only studies with accessible full texts, either through institutional subscriptions or open-access platforms, were included. This criterion allowed for an in-depth analysis of methodologies, findings, and conclusions, which was critical for maintaining the rigor of the systematic review. * Thematic Relevance: Each study was evaluated for alignment with the review's scope and objectives. Only research explicitly addressing energy management within hierarchical, multi-agent, or robust systems--particularly in the context of P2P energy trading--was retained. This ensured that the review focused on the literature directly contributing to the understanding and resolution of the research problem. Records failing to meet all of the above criteria were excluded. To ensure consistency and reduce potential biases, the screening process was conducted independently by two reviewers. Any discrepancies or disagreements were resolved through discussion and consensus. During the screening phase, each study underwent a binary evaluation process, focusing on the review of titles and abstracts to ensure compliance with the predefined inclusion criteria. Of the initial 244 records identified, 182 studies (74.9%) satisfied all criteria and were deemed relevant to the research topic. These criteria included the publication year, document type, language, full-text availability, and thematic relevance, ensuring that the selection of high-quality studies aligned with the research objectives. Figure 2 provides a statistical overview of the results obtained during the Screening phase. According to Figure 2, the 182 selected studies were distributed across two sources: 74 records originated from Scopus, while 108 were retrieved from WoS. This distribution emphasizes the complementary coverage of these databases and their collective value in ensuring a comprehensive and diverse dataset. The temporal analysis of the selected studies revealed  
Figure 2: Screening phase bibliometric statistics. a clear upward trend in the research output over the years. Between 2014 and 2018, the number of publications was relatively modest, with incremental growth: 1 study in 2014, 3 in 2015, 8 in 2017, and 4 in 2018. Beginning in 2019, a noticeable increase emerged, with 10 studies published that year. This growth accelerated further in subsequent years, with 14 publications in 2020, 24 in 2021, and 35 in 2022. The trend peaked in 2023 and 2024, which recorded 34 and 49 studies, respectively. This trajectory reflects the rising academic interest and recognition of the significance of this research domain in recent years.