1. Salesforce Help: Consumer Goods Cloud Data Model - Promotions. The official Entity Relationship Diagram (ERD) for Promotions clearly illustrates the direct relationships between the Promotion object and the Promotion Channel, Promotion Product, and Promotion Product Category objects. These junction objects are essential for defining the scope of a promotion.
2. Salesforce Help: Promotion Object Fields in Consumer Goods Cloud. The documentation for the Promotion object details its relationships. The related lists on the Promotion page layout explicitly include Promotion Channels, Promotion Products, and Promotion Product Categories, confirming these are the primary associated objects for defining its applicability.