Is it possible tp organize projects?
For example, if in Microsoft File Explorer, you click on one of the top tabs, it organizes files alphabetically / date / size, et cetera.

I have tried clicking on the tabs in BOINC to organize my projects (either alphabetically, or by time to completion, et cetera), but have had no success. Is there another way to do it (if at all possible)?

Download BOINC 5.9.3 (alpha version, not quite stable), or wait for it to be stable and become 5.10. It lets you sort projects, and workunits, and transfers, by clicking the "top tabs".

Here's the page to get the alpha version.

You can also keep track of changes between releases here.