You can easily change the group field output style with layout override feature. Output now coming as table formate and you can chagne it to any style you want.
This feature is only available on PRO version for XCF.
Extensions > Templates and click on your default template name from
On template editing screen click on the
Create Overrides tabs and click
Edit Override File
Now go back to editor tab and you will see a folder name
html > layouts > joomla. Open
Now open the file and edit the code the way you want to output the fields.