If you mean that you are working on sample.psd, then you make changes and save it as sample1.psd, continuing to work on sample1.psd. I can confirm that this occurs on a Windows system while running the latest version 26.1 of Photoshop. Photoshop automatically updates and allows me to continue working on the last saved version with a different name when using Save As. However, when using Save a Copy > save as sample2.psd, it will not automatically update to the newly saved document; it will retain the parent document for edits.
If I understand your question correctly, use "Save a Copy" to save the layered file and continue editing the parent document.