You would have to file an Individual tax return for the City of Cincinnati to get a refund of the taxes you paid that were not due. Here is a link to the form:

https://www.cincinnati-oh.gov/finance/income-taxes/2020-tax-forms/2020-individual-tax-return/

Thank you Thomas. If you have time, please see the blurb on the City of Cincinnati's website: https://www.cincinnati-oh.gov/finance/income-taxes/ 

Since I cannot take a refund from Cincinnati, could I get a tax break from the State of Indiana or on my Fed return?

Refunds for days worked at home during the Covid-19 Emergency

Under Ohio House Bill 197, during the Covid-19 Health Emergency employers were expected to withhold Cincinnati tax for employees working from home rather than their normal work location within Cincinnati, regardless of the location of their home. This would be for the duration of the health emergency plus 30 days. Therefore, there is no refund opportunity when filing a tax return for 2020 if you are working at home due to Covid-19.

The State of Indiana will give credit for taxes paid to another state. The credit is based on Indiana's tax rate. This is done on the Indiana State return. 

There is no "tax break" on the federal return other than the opportunity to itemize and claim all state income taxes paid.