title: Leaflet Layer Control: select Layer inside Layer Group?
body: <p>I would like to have a Leaflet Layer Control where I can select one of the base layers, and have this base layer itself be a LayerGroup from which I can select sublayers to display. I'm thinking of a setup where I click a radio button to select the base layer (the layer group), and under that I would then see a list of checkboxes for which layers within that to show. Is there a way to do this using the stock Layer Control?</p>
  
  <p>I looked for examples and thumbed through the Leaflet API but didn't find anything like this.</p>