I'm working on a map that displays the trips I've taken. I've created many markers and lines to designate locations and the paths between them. I've created trips using the required markers/paths and added them as layerGroups to a layerControl. The problem is several locations and drive paths have been used in multiple trips. I'd like to have multiple layers render but the problem is unchecking one layer will turn off markers/paths that are common with other still active layers.
Trip 1 = Burlington, VT marker -> BurlingtonToAlbany path -> Albany, NY marker ->AlbanyToDC path -> Washington DC marker
Trip 2 = Boston, MA marker -> BostonToAlbany path -> Albany, NY marker -> AlbanyToSanDiego path
Both trip 1 and trip 2 display properly. However, when I turn off trip 1 all related markers/paths are removed. This includes the shared Albany, NY marker and Trip 2 is no longer rendered correctly. How can I best resolve this?