To create a new Context click the Wheel Button at the bottom left of the Organize window (1) and select "Add Context".
A new context named "untitled" is added and opened for editing (1). As the name of the context is already preselected, you can immediately start typing in your context name and the default name is overwritten.
Start typing "Team Meeting" and press Return on your keyboard to save the new project name.
Now drag the newly created context (1) and drop it on the context "Situation" (2). This way "Team Meeting" became a subcontext of "Situation".