A role-playing dimension is a dimension that can filter related facts differently.
In Power BI, a role-playing dimension is a technique where a single dimension table is used in multiple ways within a fact table, each representing a different role or context. This is often used with date dimensions, where the same date table can be used to filter facts by order date, ship date, and delivery date, for example.
Example:
Single Dimension Table:
A role-playing dimension uses one physical dimension table to provide context to multiple facts within a fact table.
*-> Multiple Relationships:
This dimension table is related to the fact table multiple times, each relationship serving a different purpose or role.
Reference:
https://learn.microsoft.com/en-us/power-bi/guidance/star-schema