Sum calculation on Merged Dimension

Dear All.

I have two query as below :

Q1:

Q2:

And I Merged dimension as below

The result that I want to return:

However, When I remove GL Account, V_Amount return the wrong result

- The first:

I had set the formula for

V_Amount =

If IsNull([Amount Local Credit]) And IsNull([Amount Local Debit])  Then 0

Else (Sum([Amount Local Credit] - [Amount Local Debit]) ForEach([[Financial Statement Item]]))

But it's not working. Please help me to resolve this problem !!!

- The second:

I want to calculate for Node_Level: 2,3,4

Node_Level 2 = Sum(Node_Level 3)

Node_Level 4 = Sum(Node_Level 4)

Node_Level 4 = Sum(Node_Level 5)

I have 2 dimensions: Node_Number and V_Node_Parent to describe the relationship between node levels

How could I do it???

Thanks and best regards.