@sankarr26533925 the best practice to use Coral UI3, but not mix of both
coral UI2 and coral UI3 .Also, please check below which has multifield
with textfield in Coral UI3. You can also compare with your dialog.xml
and see what is missing.
https://aemhints.com/2020/10/24/coral-multifield-aem65/More info
regarding Coral UI2 & 3 :
https://developer.adobe.com/experience-manager/reference-materials/6-4/granite-ui/api/jcr_root/libs/granite/ui/components/legacy/coral2/coral2in3.html
https://developer....