Sometimes it can be useful to split a Video clip, for example to add commercial breaks to a feature film.
Select the video you want to trim in the Workbench or the Timeline.
Press command T or use the Trim Clip button in the lower right of the Inspector to open the Trim editor.
Move the CTI to the position you want to do the split.
Press the Split Clip button in the lower right of the Trim window to split the Video at the selected position.
The second part of the split is loaded for more splits.
Please see the chapter 4.5 Trim Window for more information.
Splitting a movie which is already loaded into the timeline loads only the first part, the second (and all following parts) have to be loaded manually to the timeline.