How to add sup product under main product using admin panel

[hemantha]

I have to solve this problem, I have Main Product need to add relevant sub product under that Main product and list down it. This should I work in this scenario from Admin panel

Collection
    |
    |----- Main Product 1
    |                |
    |                |----- MP1 Sub Product 1 
    |                |----- MP1 Sub Product 2
    |                |----- MP1 Sub Product 3
    |
    |----- Main Product 2
    |                |
    |                |----- MP2 Sub Product 1
    |                |----- MP2 Sub Product 2
    |                |----- MP2 Sub Product 3
    |                |----- MP2 Sub Product 4
    |
    |----- Main Product 3
    |                |