If you're talking about playlists you've created on an old account - if they're not deleted and they're added to the old profile, you can find them there. If the playlists are set to Private, I'm afraid that there's no way to view them even if you access the old profile from your current one.
Links to the playlists will still work, but searching for them by name in the app might not always show results.
Don't hesitate to reach out again if you have questions.
Help others find this answer and click "Accept as Solution".
If you appreciate an answer, maybe give it a Like.