How to fetch data from Receivables to AP in Descriptive Flexfield ?

Hello,

I have created 3 new DFF on Invoice header (AP)

1,Sales Order Number

2,Transaction Type

3,Transaction Number

Please Find the attachment (Screenshot)

Requirement :

Requirement 1 : All  3 new DFF coming mandatory i want to setup these three to OPTIONAL

Requirement 2 : Is it possible to fetch data from AR ?

Example : Created 1 transaction in AR which is showing Transaction Number and Sales Order Number

Now i'm going to AP and created invoice when i will click the created DFF Sales Order Number and Transaction Number (LOV) system will automatically fetch data of transaction numbers and sales order number

Need your suggestions

Regards,

Sheryar.