When you choose to create a new message definition file from an XML Schema file, you are presented with the following panels:
The panel field
lists the message set projects that are available in your workspace. By clicking
on the '+' symbol to the left of the project, these expand to list the message
sets and the XML Schema files that are available for you to select. Message
sets are filtered to only show artifacts in the active working set.
The panel field shows the complete file directory if Browse... is clicked.