To prepare oranges, place orange slices in a medium saucepan; cover with water. Bring to a boil; drain orange slices on paper towels.
Combine sugars, 1 1/2 cups water, liqueur, and salt in a medium saucepan. Bring to a boil (do not stir); reduce heat and simmer, without stirring, until a candy thermometer registers 220° (about 8 minutes). Add orange slices; simmer, without stirring, 45 minutes or until peel becomes translucent. Remove orange slices from syrup with a slotted spoon; drain on parchment paper for 5 minutes or until cool enough to handle. Place on a wire rack, and cool completely. Cut orange slices into quarters.
To prepare ganache, place milk in small microwave-safe bowl. Microwave at HIGH for 1 minute. Add chocolate chips; let stand 5 minutes, stirring occasionally until chocolate melts. Serve orange wedges with ganache.