I amended my 2016 tax return & received an additional refund in 2018. Do I report the total refund on my 2017 return or wait until my 2018 return to report the extra?

did you amend your state return and receive an additional state refund ?

yes, I amended both federal and state and got small refunds from both

No.  Your additional federal refund is not taxable; you do not enter it on your tax return.