While watching a movie or Tv show (not live Tv)
You can skip forward and back using the directional buttons.
Multiple press of one of the arrows will jump more than a single press.
For advanced use you can decide how much each press will jump by adjusting the setting at Settings/Video/Playback but the standard settings are perfect in my opinion.
You can also use the number buttons on the remote control. For example pressing 2344 and then pressing OK will jump to 23mins 44 secs
If this doesn't work for you it's due to the link you're using not supporting it but most links do support it.