Help creating a dynamic dropdown pick field

Help creating a dynamic dropdown pick field

I am trying to segment all of my contacts and account types into INDUSTRY and INDUSTRY-TYPE as a sub category.

Inherently this means that I would have a dynamic pick field (dropdown list) based on INDUSTRY that dictates the subcategory "INDUSTRY TYPES" where the only available choices are for their specific INDUSTRY. 

For Example:
Contact 1
  1. INDUSTRY = Bank (which dictates TYPE) 
  2. TYPE = choice of (Commercial, Investment, Retail)
Contact 2
  1. INDUSTRY = Brokerage  (which dictates TYPE) 
  2. TYPE = choice of (Independent, Insurance, Wirehouse) 

Need some help