There are a couple of common sets of sub-fields out there that you may find helpful. AACSB International reports a list that includes

Accounting,Behavioral Science/ Org Behavior,

Bus Communication,

Bus Education,Bus Ethics – incl Corp Soc Resp,

Bus Law/ Legal Environment,

CIS/ MIS,

E-Bus – incl E-commerce,

Econ/ Managerial Economics,

Entrepreneurship/ Small Bus Admin,

Finance – incl Banking,

General Bus,

Health Services/ Hospital Admin,

Hotel/ Restaurant/ Tourism,

HR Mgt – incl Persnl & Ind/Labor Rel,

Insurance,

International Bus,

Management,

Marketing,

Operations Research,

Production/ Operations Mgt,

Public Administration,

Quantitative Methods,

Real Estate,

Statistics,

Strategic Management,

Supply Chain/ Transport/ Logistics,

Taxation,

Other

The US Department of Education uses a different list with more divisions for business degrees. It includes

52-Business, management, marketing, and related support services.

52.01-Business/Commerce, General

52.0101-Business/Commerce, General

52.02-Business Administration, Management and Operations

52.0201-Business Administration and Management, General

52.0202-Purchasing, Procurement/Acquisitions and Contracts Management

52.0203-Logistics and Materials Management

52.0204-Office Management and Supervision

52.0205-Operations Management and Supervision

52.0206-Non-Profit/Public/Organizational Management

52.0207-Customer Service Management

52.0208-E-Commerce/Electronic Commerce

52.0209-Transportation/Transportation Management

52.0299-Business Administration, Management and Operations, Other

52.03-Accounting and Related Services

52.0301-Accounting

52.0302-Accounting Technology/Technician and Bookkeeping

52.0303-Auditing

52.0304-Accounting and Finance

52.0305-Accounting and Business/Management

52.0399-Accounting and Related Services, Other

52.04-Business Operations Support and Assistant Services

52.0401-Administrative Assistant and Secretarial Science, General

52.0402-Executive Assistant/Executive Secretary

52.0406-Receptionist

52.0407-Business/Office Automation/Technology/Data Entry

52.0408-General Office Occupations and Clerical Services

52.0409-Parts, Warehousing, and Inventory Management Operations

52.0410-Traffic, Customs, and Transportation Clerk/Technician

52.0411-Customer Service Support/Call Center/Teleservice Operation

52.0499-Business Operations Support and Secretarial Services, Other

52.05-Business/Corporate Communications

52.0501-Business/Corporate Communications

52.06 52.06-Business/Managerial Economics

52.0601-Business/Managerial Economics

52.07 52.07-Entrepreneurial and Small Business Operations

52.0701-Entrepreneurship/Entrepreneurial Studies

52.0702-Franchising and Franchise Operations

52.0703-Small Business Administration/Management

52.0799-Entrepreneurial and Small Business Operations, Other

52.08-Finance and Financial Management Services

52.0801-Finance, General

52.0803-Banking and Financial Support Services

52.0804-Financial Planning and Services

52.0806-International Finance

52.0807-Investments and Securities

52.0808-Public Finance

52.0809-Credit Management

52.0899-Finance and Financial Management Services, Other

52.09-Hospitality Administration/Management

52.0901-Hospitality Administration/Management, General

52.0903-Tourism and Travel Services Management

52.0904-Hotel/Motel Administration/Management

52.0905-Restaurant/Food Services Management

52.0906-Resort Management

52.0999-Hospitality Administration/Management, Other

52.10-Human Resources Management and Services

52.1001-Human Resources Management/Personnel Administration, General

52.1002-Labor and Industrial Relations

52.1003-Organizational Behavior Studies

52.1004-Labor Studies

52.1005-Human Resources Development

52.1099-Human Resources Management and Services, Other

52.11-International Business

52.1101-International Business/Trade/Commerce

52.12-Management Information Systems and Services

52.1201-Management Information Systems, General

52.1206-Information Resources Management/CIO Training

52.1207-Knowledge Management

52.1299-Management Information Systems and Services, Other

52.13-Management Sciences and Quantitative Methods

52.1301-Management Science, General

52.1302-Business Statistics

52.1304-Actuarial Science

52.1399-Management Sciences and Quantitative Methods, Other

52.14-Marketing

52.1401-Marketing/Marketing Management, General

52.1402-Marketing Research

52.1403-International Marketing

52.1499-Marketing, Other

52.15-Real Estate

52.1501-Real Estate

52.16-Taxation

52.1601-Taxation

52.17-Insurance

52.1701-Insurance

52.18-General Sales, Merchandising and Related Marketing Operations

52.1801-Sales, Distribution, and Marketing Operations, General

52.1802-Merchandising and Buying Operations

52.1803-Retailing and Retail Operations

52.1804-Selling Skills and Sales Operations

52.1899-General Merchandising/Sales/Related Marketing Operations, Other

52.19-Specialized Sales, Merchandising, and Marketing Operations

52.1901-Auctioneering

52.1902-Fashion Merchandising

52.1903-Fashion Modeling

52.1904-Apparel and Accessories Marketing Operations

52.1905-Tourism and Travel Services Marketing Operations

52.1906-Tourism Promotion Operations

52.1907-Vehicle and Vehicle Parts and Accessories Marketing Operations

52.1908-Business and Personal/Financial Services Marketing Operations

52.1909-Special Products Marketing Operations

52.1910-Hospitality and Recreation Marketing Operations

52.1999-Specialized Merchandising, Sales, and Marketing Operations, Other

52.20-Construction Management

52.2001-Construction Management

52.99-Business, Management, Marketing, and Related Support Services, Other

52.9999-Business, Management, Marketing & Related Support Services, Other