When in the Videos Saved Locally View or when in the Videos Saved in Cloud View, by swiping down, you can bring up a text box to search for videos with names that contain what you type into the text box. By swiping left on a video entry, you can cause an Edit Button and a Delete Button to appear.  Tapping the Delete Button will remove the video from local or cloud storage as the case may be.  Swiping all the way to the left will also cause the video to be removed.  Tapping the Edit button will bring up an alert that will enable you to rename the video.