On a Cash flow statement were would you put amortization of trademarks?

If it's indirect, it's added in the operating section. It's a non-cash expense, so it was deducted from net income, but no cash was paid for it. So you have to add it back in.

If it's direct, it's not included anywhere.

Just as a note, it's not relevant that it's a trademark. Depreciation of plant assets and amortization of intangibles all works the same way.