You can string two or more attributes together using the Composite text attributes. Composite text attributes are available for Items, occurrences and products and allow you to concatenate values in existing attributes into a new text value in a separate attribute.
A description of how to create a composite text field is placed under Edit Item Composite Text Attributes.
To be able to create composite text for Occurrences, you choose it under Items in the settings menu
The way it is set up is the same as for Items or products, the only difference being that the fields you can add are from the occurrence field picker.