Is it possible one kmz file to have many kml files?
If yes, how can I convert the kml files to a kmz in order to be able to show them in GoogleEarth?
In case of one kml file, I read that its enough to place the kml in a folder, zip it and change the extension. I tried that and it works. But in the case of many kml files, it only shows the first one taken from the list:
When Google Earth opens a KMZ file, it scans the file, looking for the first .kml file in this list. It ignores all subsequent .kml files, if any, in the archive. If the archive contains multiple .kml files, you cannot be sure which one will be found first, so you need to include only one (link)
Best Answer
From the Google Developers help for Keyhole Markup Language it is clear that Google Earth will only use one KML file from a KMZ no matter how many you put into the folder you zip up to create it: