Connected Drop down is not working, It it getting auto prepopulated

I have created two DocTypes
First is Supplier Configuration(Id, Supplier Company Name, Supplier Name, Contact Details).

Id  Supplier Company Name,          Supplier Name,          Contact Details
1   Company1                          Rajesh                9090192011
2   Company2                          Shiva                 9090199211
3   Company2                          Shiva                 9021343333

Second is Supplier RFQ List(Id, Supplier Company Name, Supplier Name, Quotation)
I have linked Supplier Configuration with Supplier RFQ, I want to design two drop down, When we select Supplier Company Name in first drop down, like Company2, now in second drop down show the list of Supplier Name. How ever If here is give me Supplier Configuration field and when I select any value, other values like Supplier Company Name and Supplier Name is auto filed. I don’t need that, Can anyone tell how to achieve required drop down?

Exp: