Would you like to know the subject categories that are possible for placing a book on the shelf of a retail bookstore? Then check out http://bisg.org/standards/bisac_subject.
They list all sorts of categories, including more than 130 subcategories for Business and Economics. While most bookstores won't use that many categories, the BISAC subject categories should help you narrow where your book fits in a bookstore.
To supplement this online research, of course, you also need to visit some real brick-and-motar bookstores. Check where they shelve books like yours. What is the signage above the shelf? What categories do the books on that shelf display on their back covers? Ask the bookseller as well for suggestions on where your book should be shelved.
When you have finished your research, then put the one or two categories where your book should be shelved on the top left corner of your book's back cover. That way you can ensure that your book will find its best fit in most bookstores.