When I try and export from lightroom I get the export screen. Then when I look at the right side where there is the : Intermediate file Format Output path I can see the most recent output paths I previously used. But the button to search / select a new output path location is not visible / available. no matter how I change the screen size I still can't see / access that field. See attached photo for missing field

This is a Lightroom issue and can happen, if there is a very long path in the list of the recent output paths.
To fix this, click on the selector for the recent output paths and choose "Delete List". After that you might have to reopen the dialog, but the layout will be fixed and you'll be able to see the button.

I have had this issue for years and yes I would simply click the "Delete List", close the dialogue box then re-export and the field was empty and I was able to see and browse to use the select output path. But since 2 updates ago when I Click "Delete List" it deletes the list but when I close and reopen the dialogue box the same out path selections reappear. Ie the Delete List function did not really delete the list.

You are right. I'll check and fix that.

Ok, I've analyzed the issue, it's two things:
1.) the annoying stretching of the dialog with long entries - I've finally managed to work around this. It will be fixed in 5.5 beta 5.
2.) the settings (for example clearing the list) are not being taken over when closing the dialog with "done" - but they will, when you close it with "Export". I've submitted this erratic behavior of the Done button as Bug report to Adobe, I hope they will fix it.

As a work around for your problem: clear the list, then "Export". Abort the export. Now reopen the dialog and it should be fine again. I'll publish the new beta in the next days.

Thank you for your attention and quick follow-up. You have created a very fine piece of software. It's great