https://www.sitepoint.com/html5-video-fragments-captions-dynamic-thumbnails/
above is a sample page, on the page, there is sample code to choice three sections.
it works in Chrome or Safari, but it's not work in Edge now.
https://developer.microsoft.com/en-us/microsoft-edge/platform/status/videotracks/?q=video%20track
but in this page says edge support video track.
so is this maybe a error?