Any project-scoped properties associated to the selected workflows or instances will be displayed in the Project Properties section. You can override Instance level properties by clicking on the Override Properties button.
By clicking the button between the Key Name and the Value, you can toggle the value between being a literal value and an expression.
You can filter the displayed properties by entering part of the Key Name into the Filter text box and clicking the Filter button (filters using contains operation). By clicking on the clipboard icon to the right of the Key Name, you can copy the Property Code to your clipboard.
For information on configuring these project properties see the Properties chapter Editing Project Properties