# File blah.conf
<graph>
   <node>
      title = node1
      <loc>
         x = 10
         y = 20
      </loc>
   </node>
   <node>
      title = node2
      <loc>
         x = 10
         y - 29
      </loc>
   </node>
   <edge>
      sourcename = node1
      targetname = node2
   </edge>
</graph>

# After parsing file and placing into %conf you will have
%conf = (
   node = {
      title = {
         node1 = {
            loc = {
               x => 10,
               y => 20,
            },
         },
         node2 = {
            loc = {
               x => 10,
               y => 20,
            },
         },
      },
   },
   edge = {
      sourcename => node1,
      targetname => node2,
   },
)
# You can then reference pieces thereof via
$conf->{node}->{title}->{node1}->{loc}->{x};