Managing Elasticsearch data across multiple indices can be streamlined using Filebeat, Index Lifecycle Management (ILM), and data streams, as demonstrated by Hung Nguyen. Filebeat is a lightweight log shipper that efficiently collects, parses, and manages data from various sources into Elasticsearch, offering prebuilt Kibana dashboards for visualization. The process involves creating specific index lifecycle policies for different data retention needs, such as keeping Google Cloud data for 30 days and Azure and AWS data for 365 days. By leveraging data streams and Elasticsearch index and component templates, users can avoid common sharding issues and ensure data is separated based on its source, enhancing management efficiency. The approach enables application of distinct data retention policies, selective data access, and tailored data availability, all while simplifying complex document-level security configurations. The blog provides a practical example of managing cloud data sources and offers a step-by-step guide to setting up the system, encouraging users to try it and explore additional features like Elastic Observability for comprehensive ecosystem insights.