This is going to be very simple for anyone with experience with views arguments.
I have a node type called 'itinerary' withc is a parent content type and then i use a node reference field to reference several child nodes of type 'destination'.
I then have a gmap location view which displays node locations on a map, this view just has node titles which show up as markers on a single map. This view works fine and can be filtered and manipulated in the same way as any view.
What I need is to display this view in a block, and only have nodes appearing in the view if they are referenced nodes (destinations) from the parent node which is currently display on the page (the itinerary).
I know this can be done in views by having an argument on the node reference field which checks the URL for the nid and then the view only displays the nodes which are referenced by the node currently displayed on the page, therefore only the markers for the destinations referenced by this itinerary are displayed on the map.
Should be very easy but cant get it to work.