There is no set formula for how to structure a discussion. But that does not mean you should not think carefully about how to do this. Your specific area of study will possibly require a particular general structure (for example, a project on history might call for a chronological organization), and your specific topic might require you to organize the discussion in a way that reflects this topic (for example, a study of several poems might require you to have a subsection on each work). Whatever the case, some kind of division will help you to present your work effectively and make it easier for your readers to follow it clearly.  

In humanities papers, the most common divisions within the discussion are subsections (“1.1 The Rise of the Novel”; “1.2 The Condition of England Novel”; “1.3 The Modernist Novel”, etc.) or chapters (“Chapter One: The Georgian Garden”; “Chapter Two: The Georgian Market Town”; “Chapter Three: The Georgian Slums”).  

Subsections are units that are more closely interconnected; chapters are units that are more stand-alone in content. You will almost certainly have decided on this by the time you come to write your discussion (as you will have already drawn up your table of contents); but, during your writing, look carefully at your work and keep in mind that your chosen general structure might need changing.