How to create the approval rule for child budget

Hi Team,

Would require you urgent assistance for Approval rule creating for the child budget. Initially I have created one root budget (Master budget) and then I created one more and while creating the another I put the earlier Budget name under the option "Parent budget" so that the later one will be the child of the earlier one. All things are fine I got approval for the earlier (Parent budget) budget also as per the setup defined.

However, when I sending the approval to the Child budget, in the view approval window I am getting the statements which says as follows