Move Child Range from source parent to target

[ora7_sun7]

I want to know how the data gets deleted from the base table fnd_flex_value_norm_hierarchy, when the user clicks "Move" button (steps below) to move the child range from Source parent flex value to Destination parent flex value. I checked all the APIs and went through the form FNDFFMSV.fmb, but couldn't detemine the process which deletes the data from the table at the child level. Please let me know your suggestions.

Responsibility: Sys Admin
Navigation: Validation --> Value-->
Enter value set and flex value
Click Move Child Range tab and select the source parent and target parent and check the child of source parent and click "move" button to complete the transfer process.

Thanks,
Sunny