Fields should be populated based on the previous column from the custom table

[suvi1]

I am having a Question,

 I am having a Cusotm table, lets say table data 1

 with 4 columns  Business Unit, Business world, Business city and Business Area.

 i want to display the above 4 field s on the service catalog form , all should come from the table dynamically.

1. Business Unit

2. Business World should be displayed based on the Business Unit value selected  on the Business Unit.

3.  Business City list should be displayed based on the combination of Business Unit  and Business World.

4.  Business Area values should be displayed based on the combination of Business Unit,Business World and Business City.

  Some one please help me on the solution approach.