Value streams and processes focus mainly on those areas which ensure integration and coordination of various actions and parts which contribute towards better value creation for the organization. This dimension is more concerned about the way the organization has organized the activities or processes and how it enables and ensures the value creation across all stakeholders.
https://www.knowledgehut.com/tutorials/itil4-tutorial/itil-four-dimensions-it-service-management

Obtain/build is one of the six activities of the service value chain, which is a set of interconnected activities that an organization performs to deliver a valuable product or service to its consumers and to facilitate value realization1. Obtain/build activity relates with buying new products, as well as designing, developing, and testing new or changed service components2. This activity ensures that service components are available when and where they are needed and meet agreed specifications3. Reference: ITIL Foundation - ITIL 4 Edition, page 10; ITIL 4 - A Pocket Guide, page 21; ITIL 4 Practice Guide: Service Value Chain, page 9.

The purpose of the service configuration management practice is to ensure that accurate and reliable information about the configuration of services, and the CIs that support them, is available when and where it is needed. This includes information on how CIs are configured and the relationships between them.
https://wiki.process-symphony.com.au/framework/lifecycle/process/service-configuration-management-itil-4/