Prepare a function map, detailed duties, decision-authority records and evidence identifying the people who execute the function. Business records should explain why the activity is essential and how the beneficiary manages it.
Use work products with context
A budget approval or governance decision can illustrate management when its author, scope and effect are clear. A technical report written by the beneficiary may instead show operational work, depending on the facts. Explain how each exhibit relates to management rather than relying on its impressive appearance.
The U.S. support structure needs its own evidence, even when the foreign function has already been documented. Prefer material that shows the position operating rather than material that describes it.
Minutes recording a decision the person took, a policy issued under their name, an approval they granted, a budget they signed off, a supplier they selected, or an external report addressed to them in that capacity all demonstrate the role in motion. Provide the surrounding context for each, since a single page lifted from a longer document rarely explains itself. Where work products are technical, add a short plain-language note stating what the document is and what it shows about the person's authority.
Be selective: a small number of well-explained items generally does more than a large appendix. And check that the documents are consistent with each other on dates, titles and reporting lines before any of them is chosen.