In Writer, Calc and Impress, we have a Find Previous button the Find toolbar, but none in the Find & Replace dialog. Instead a user has to open up 'Other Options' and check the 'Backwards' checkbox to be able to find in reverse. So lets add a Find Previous button and remove the 'Backwards' checkbox.
This would be helpful, placement of the button in the reworked dialog (bug 98539 with one horizontal row) may be an issue.
@Stuart: Not really an issue as most find & replace dialogs are always wide.
Akshay Deep committed a patch related to this issue.
It has been pushed to "master":
tdf#98417, tdf#98539: DIALOG: Improvements to the Find & Replace dialog.
It will be available in 5.2.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.