Role-Playing dimensions result in "Duplicate Joins detected" error

I want to create a Mondrian Cube in Pentaho for routes with the following information that includes two role-playin dimensions

Facts

• Number of passengers
• Income

Dimensions:

• Country -> City (Role: Route_origin)
• Country -> City (Role: Route_destination)
• Year -> Month -> Day

The Pentaho Data Source Wizard ask me about the tables and relationships that need to be used. I tried to create the cube reusing the Country -> City Dimension table but the Wizard complains with the message: Duplicate Joins detected: That join condition already exists. Check the table and join key and try again.



Should I create two different tables with the same data? If not how I am supposed to do it?