Supplier merge parent and child relationship

Summary:

We are planning to use Supplier merge but we still want supplier to have access to old Supplier profile.

One of the note mentioned that we can use supplier parent and child relationship. So I assigned 'To Supplier' as parent to 'From Supplier'

But though I assined 'To Supplier' as parent on the 'From Supplier', th 'To supplier' contact is still not able to see child supplier.

Can you some one provide guidance on how we can make Parent supplier contact see child supplier after supplier merge??

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