You are using the Knowledge Discovery feature of the Data Quality Services (DQS) client application to modify an existing knowledge base. In the mapping configuration, two of the three columns are…

Adding a column mapping alone is insufficient because a mapping requires a target domain; without creating a domain first, the mapping cannot be completed for Team Type.

Mapping a composite domain to a single source column is incorrect because composite domains are designed to span multiple related columns, not to handle a single unmapped column.

Creating a composite domain that includes Team Type would bundle it unnecessarily with other domains, adding unneeded complexity for what is a single-column mapping requirement.

In the DQS Knowledge Discovery mapping step, each source column must be associated with a domain that defines the data rules and values for that column. When a column like Team Type has no existing domain, you must add a new domain directly from the mapping configuration page. This creates a dedicated domain that the Knowledge Discovery process will then populate with discovered values.