[op03]

Google Sankey diagrams Budgets. There are lots of tools - eg - https://github.com/ricklupton/floweaver, sankeymatic.com etc

Not my area but complications in visualizing flows dramatically increase when the flows criss cross. Even small budgets start looking like chaotic weaving.

Which I think is why we still have buildings full of accountants and analysts to make sense of what is going on even though lots of people have access to the data.