Organizational charts can be difficult to find as they are often considered proprietary information. Try:
Searching within annual reports
See Mergent Online. Search for a company. In the company profile, select the Annual reports tab.
See Mergent Intellect. Search for a company. In the company profile select Annual reports within the Company Details tab.
Annual reports can also be found using SEDAR (Canada) and EDGAR (US)
Search the name of the company AND organizational structure in ABI/INFORM, Business Source Complete, or Nexis Uni. You may find articles discussing the internal structure of the company.
Google the name of the company and organizational chart (ex. starbucks organizational chart)