The navigation rules are defined in faces-config.xml.
So, if i had fragment1.jspf inside Page1.jsp and a button inside the page fragment which on click should take me to Page2.jsp
My navigation rule in faces-config would look something like:
<navigation-rule>
<from-view-id>/Page1.jsp</from-view-id>
<navigation-case>
<from-outcome>foo</from-outcome>
<to-view-id>/Page2.jsp</to-view-id>
</navigation-case>
</navigation-rule>
Where the action handler for the button returns "foo"
Ahh well.. If you are using the same page fragment in a large number of pages
maybe you could then just expand the scope for from-view-id to "/*" and make sure that none of the other buttons return the same action string..
Unless you want the button on the page fragment to redirect to different pages depending on the page it is on..