If you are in Ohio, you only pay school district income tax (SDIT) to the SD you live in. You do not pay SDIT to the district you worked. SDIT is different from Ohio City income tax, where you are taxed by both the city you live in and the city you live in.
If your employer mistakenly withheld tax for the work location SD, you will have to file a 2nd SD return to get a refund. Unlike city tax, you do not get a credit from the resident SD for SD tax paid to another SD.