Heading down the rabbit hole…
Where the Expeditionary Force books go. The books give no coordinates, so apart from Earth each world's spot is approximate. Choose a story to see where it goes, or a place to see what happens there.
Star positions from the HYG database by David Nash (CC BY-SA 4.0). The Milky Way around them is drawn, not surveyed: its arms are an impression that puts the Sun on the Orion Spur, 26,000 light years from the centre.