1. Huawei iMaster NCE-Campus V300R021C00 Configuration Guide (Cloud-based) - Site Template Configuration: This official guide explicitly describes the template structure. It states, "Site templates are classified into site group templates and site templates. A site group template defines common configurations for sites in a site group. A site template defines configurations for a specific site. A site template can inherit configurations from a site group template." This directly confirms the hierarchical and inheritance relationship.
Source: Huawei Enterprise Support Documentation, "Site Template Configuration" section.
2. Huawei iMaster NCE-Campus V300R022C00 Product Documentation - Principles of Template-based Site Configuration: This document details the underlying principles of the feature. It explains that configurations are defined in templates which are then applied to sites. The concept of applying a template to a "Site Group" inherently creates a parent-child relationship where individual sites within the group inherit the group's template settings.
Source: Huawei HedEx Lite, iMaster NCE-Campus Product Documentation, Section: "Provision > Physical Network > Site Configuration > Principles".