I would like to expand the categories in my layer control in leaflet.

The advice in the links below:

https://leafletjs.com/examples/layers-control/ Adding Layer control in Leaflet?

show the control layer categorized on 2 categories only.

I tried to make 3 of them:

   var baseMaps = {
    "Open Street Map": osm,
    "OSM B&W":OpenStreetMap_BlackAndWhite,

   var overlayMaps = {
    "Geographic names": positronLabels,

    var planners = {
    "Gavin Sinclair": gavin,
    "Loide": loide,
    "Sam": sam,
    "Jordan": jordan,
    "Steve": steve,
    "Danny": danny

     //Add layer control
   L.control.layers(baseMaps, overlayMaps, planners).addTo(map);
      //////////////////////---------------------------------------------------end of map layer section -------------------------

But only forst two are shown.

How about 3rd one?

enter image description here

Moreover is it possible to have some basic dropdown list possible?