The nondeductible traditional IRA contribution made for 2022 was required to have been reported on Form 8606. If you did not do so, you must amend. The $6,000 on line 14 of that form carries forward to line 2 of your 2023 Form 8606.
The $12,500 of Roth conversions performed in 2023 are entirely reportable on your 2023 tax return on 2023 Form 8606. There is nothing to separate.
