cost allocation by sql query

Hello Experts,

I want to allocate cost in top down approach via SQL i.e
user input should be
1.Expense amount for node 1 (which need to be allocate in lower nodes)
2. Percentage of allocation for each nodes

              Node 1
      Node 2             node3

node4        node 5     node 6    node 7

if node 1 gets 100 rupee.then it should get allocated in node 2 and node 3 in 40-60%(User input).
also it should get allocated further in node 4 and 5 basis user input percentage and also in node 6 and 7.

Thanks