Yes, you can.
You are able to find Not a Fit candidates from the upper right corner of your search results page.
When you click on the link, you can review the list of these candidates, give Good Fit to them or use the Recover button to add them back to the search results list. You may also select multiple candidates and give feedback to them with the two buttons above the column.
Rejected candidates can be found on your pipeline page, as they have been selected from the search results and were included in your pipeline.
You can add them back to the pipeline stage using the Recover button. If you want to move them to other stages, click on the small triangle sign on the side of the button and select the exact stage from the drop-down menu. Likewise, you are able to bulk edit these candidates by ticking the boxes on the left and using the button on top of the candidates' list.