The mepo_ui_menu_route_overpassrelation.sh script allows a user to visually display an OSM relation by id on the map as an ordered pin group; thus can be used for public transit etc.. However to get the input OSM id we should support querying for user input for a region.
Like if you're viewing Mexico City; you should be able to just put in "Mexico City Metro" and then pick from the different subway lines. Currently these ids are hardcoded - this should be removed.
Should be doable via overpass query to lookup all relations in bounding box.