Symbolizing a layer by unique values where the layer has a definition query applied, and the field to be symbolized has a domain applied, returns all values from the domain rather than only the values that satisfy the layer's definition query.
1. Create a new field to be used to symbolize the layer. 2. Use the Field Calculator to populate the new field's values with the values from the field where the domain is applied. 3. From the Value Field drop-down list, select the new field name to symbolize the layer using the new field.