root
    |
    a
   /
  b   c
 /   /
d  e  d e

root
    /
   d   e
   |   |
   a   a
  /   /
  b c  b c

root
   /
   b   c
  /   /
 d  e d  e
 |  | |  |
 a  a a  a

root
    /
   a    b     - Projects {a, b}
  /   /
 c  d  c  e   - Budgets {c, d, e}
 |  | /  |
 f  g f g g   - Fiscal year with data {f, g}