How to format row in flutter?

for creating an Instagram like comment section UI you can check the below code. I have added a hardcoded list for display purpose you can insert your own server data with logic to differentiate between both list views. For this UI I have created a normal comment object having all replies to that user in replies list such as

single user comment object
    {
          'name': 'person 1',
          'message': 'Some text message from person 1',
          'replies': [
            {
              'name': 'person 2',
              'message': 'Some text message from person 2',
            },
            {
              'name': 'person 3',
              'message': 'Some text message from person 3',
            },
          ]
        },

import 'package:flutter/material.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  final List<dynamic> commentList = [
    {
      'name': 'person 1',
      'message': 'Some text message from person 1',
      'replies': [
        {
          'name': 'person 2',
          'message': 'Some text message from person 2',
        },
        {
          'name': 'person 3',
          'message': 'Some text message from person 3',
        },
      ]
    },
    {
      'name': 'person 4',
      'message': 'Some text message from person 4',
      'replies': []
    },
    {
      'name': 'person 5',
      'message': 'Some text message from person 5',
      'replies': [
        {
           'name': 'person 6',
          'message': 'Some text message from person 6',
        }
      ]
    }
  ];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
        title: Text("Hello World"),),
        body: ListView.builder(
            padding: const EdgeInsets.all(0.0),
            shrinkWrap: true,
            itemCount: commentList.length,
            itemBuilder: (context, index) {
              return Column(children: [
                ListTile(
                  contentPadding: const EdgeInsets.symmetric(horizontal: 8.0),
                  title: Text(commentList[index]['name']),
                  leading: Icon(Icons.fiber_new),
                ),
                ListView.builder(
                    shrinkWrap: true,
                    physics: const NeverScrollableScrollPhysics(),
                    padding: const EdgeInsets.all(0.0),
                    itemCount: commentList[index]['replies'].length ?? 0,
                    itemBuilder: (context, i) {
                      return ListTile(
                        contentPadding:
                            const EdgeInsets.symmetric(horizontal: 24.0),
                         leading: Icon(Icons.pages),
                        title: Text(commentList[index]['replies'][i]['name'] ),
                      );
                    })
              ]);
            }));
  }
}

Run this cord in dartpad and refactor it according to your use.