Duplicates in URL

My site has many instances where the section name and the category name are the same.  Therefore a lot of my URLs look like this: www.site.com/aboutus/aboutus/ .  Is there a way to eliminate this problem?  Perhaps making it so that the "section" is not included in the url.

No, Unfortunately not. It has to be in section/category/item form.

I posted this problem on the joomla board and got this response, but I am assuming SEF advance does not have this feature?

If I remember correctly, doesn't SEF Advance have an option to add a suffix to create unique FURLs?

In OpenSEF we enabled various suffixes to deal with this issue:
- append ItemID
- append Content ID
- append Date

Only way to deal with content where titles are the same.

You can add suffix in SEF Advance but you will still have section/category/item form.
The reason for this is performance. SEF Advance is the only SEF component that makes URL conversion on-the-fly, not saving URLs in database, which I believe perform better, especially on large sites.
Unfortunatelly this method is less flexible in terms of modifying URLs like skipping the section or category part.

I use Sef Advance in Mtree and have listings of the same name (title) at different address locations, but the detailed viewing page of the first listing (in alphabetical order) is always displayed for all of these listings. I have set the Preference "Unique item:" to yes but this does not seem to add any suffix to make all detailed listings unique.

The summary listings of these (of the same listing name) are ok and display different addresses & contents.

Unless there is something else in Sef Advance that I should set but have not, I hope the next version of Sef Advance would solve this problem.

My site has many instances where the section name and the category name are the same.  Therefore a lot of my URLs look like this: www.site.com/aboutus/aboutus/ .  Is there a way to eliminate this problem?  Perhaps making it so that the "section" is not included in the url.

Of course you can.
Just note the URL without any SEF enabled and then put in your alias for it under the alias section.
Of course this is if you have massive pages/content in that section a time consumpting thing..... So better would be if you deciding to change your section/categories way....

For the Suffix-Thing.... ive requested a feature-release ---> HERE <---
No idea if Saka will implement it in any future release...