How to display labels from KML in separate layers in leaflet?

Question

JavaScript

There is KML with traffic route marking

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" >
<Folder id="results">
  <name>trace name</name>
  <Style id="dir_step"></Style>
  <Placemark id="26.1.1"></Placemark>
  <Placemark id="26.1.2"></Placemark>
  <Folder id="26"></Folder>
  <Folder id="27"></Folder>
  <Folder id="28"></Folder>
  <Folder id="29"></Folder>
</Folder>
</kml>

Display it with the following code

function init(){

var map = L.map('map').setView([55.826797, 49.130057], 11);
 
L.tileLayer('map/{z}/{x}/{y}.png', {
  minZoom: 10,
  maxZoom: 18
}).addTo(map);

var track = new L.KML("kml/rathaus_trans.kml", {async: true});
                                                              
track.on("loaded", function(e) { 
            map.fitBounds(e.target.getBounds());
         });

map.addLayer(track);

map.addControl(new L.Control.Layers({}, {'Track':track}));
}

All Folder layers are displayed at once.
How to display each layer separately?