Within Teamwork Projects you may want to hide the left pane so that you are not seeing quite as much information on your screen. This can be done on any screen that the left pane shows.
You can hide the left pane by clicking the two left facing arrows to the right of the left pane as below:
To expand the left pane again simply click on the two arrows, now right facing, on the grey minimized left margin to expand it again as above.
For more information see: Changing general project settings