Yeah I think they’re preventing a person from running for multiple offices at a time or for the same office under multiple parties (you would then appear on the ballot twice for the same office)
This is just a quick perusal so I could be all wrong.
- - -
If a candidate withdraw before the applicable deadline for filing a declaration of candidacy, declaration of intent to be a write-in candidate, or nominating petition for the subsequent office for which the person is seeking to become a candidate at the same election;
then
the secretary of state or a board of elections shall not disqualify, a person from being a candidate for an office
3513.052 (G) and 3513.052 (H)(2)(a)
- - -
3513.05 Deadline for filing declaration of candidacy.
Each person desiring to become a candidate for a party nomination at a primary election or for election to an office or position to be voted for at a primary election, except persons desiring to become joint candidates for the offices of governor and lieutenant governor and except as otherwise provided in section 3513.051 of the Revised Code, shall, not later than four p.m. of the ninetieth day before the day of the primary election, file a declaration of candidacy and petition and pay the fees required under divisions (A) and (B) of section 3513.10 of the Revised Code.
- - -
When is Ohio’s primary? The cutoff is 4PM on the 19th day before the primary. A candidate does not have to file a declaration of candidacy and petition and pay the fees until then. Once they do then they can not be a candidate of another party unless they first withdraw from the first party.