In this case you can assign more than one value to a property in the Select Element dialog. Examples of properties that may have multiple values: Classifier, Method.
To assign multiple property values
- Click an appropriate property value cell.
 - Click the Edit button (see the highlighted button in the following figure). The Select Element dialog opens.
 - Select existing and / or create elements.
 - Click OK when you are done.
 
Make sure the Multiple Selection mode is turned on.
