Hi,
if your tour.xml for example lies in "http://www.whatever.com/example_tour/tour.xml" and the map.xml is in the same directory, then the include-line should look like this:
<include url="%CURRENTXML%/map.xml" />
If the map lies for example in "http://www.whatever.com/example_tour/maps/map.xml", the include-line should look like this:
<include url="%CURRENTXML%/maps/map.xml" />
The %CURRENTXML% refers to the directory where the tour.xml lies.
Best regards
Nupsi