Auto populate custom financial dimension in General ledger form

Hello All,

I am trying to auto populate ledger financial dimension values based on custom financial dimension.

My custom financial dimensions are,

1. Client Org Unit

2. Final Client

3. local Sub Industry

When i select the Client Org Unit i need to auto populate the remaining two dimension in General ledger form.

Please provide any suggestion on how to achieve this, also let me know if there are any standard class which i can look into to get any idea.

Thanks.