Iterate over firebase database nodes flutter - firebase

Question

I want to iterate through the customers available and get the posts of every customer and show it inside a listview.
However, if i specify the database reference as final postsRef = FirebaseDatabase.instance.reference().child('Customers available').child(Uid).child('Posts').orderByChild('timestamp');, I get only the user's posts.
Below is my code for building the listview and another is my database reference. Thanks final postsRef = FirebaseDatabase.instance.reference().child('Customers available')
This is my Firebase Database Screenshot
future: postsRef.once(),
builder: (context, AsyncSnapshot<DataSnapshot> snapshot) {
if (snapshot.hasData) {
lists.clear();
Map<dynamic, dynamic> values = snapshot.data.value;
values.forEach((key, values) {
lists.add(values);
});
return new ListView.builder(
shrinkWrap: true,
itemCount: lists.length,
itemBuilder: (BuildContext context, int index) {
return Container(
decoration: BoxDecoration(
border: Border(bottom: BorderSide(color: Colors.grey[200]))
),
padding: EdgeInsets.all(SizeConfig.blockSizeHorizontal * 4),
child: Row(
children: <Widget>[
Container(
height: 50,
width: 50,
child: Container(
height: 50,
width: 50,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(150),
image: DecorationImage(image: FirebaseImage('gs://tipy-98639.appspot.com/profile_pic'))
),
),
decoration: BoxDecoration(
color: Colors.grey,
image: DecorationImage(image: AssetImage('images/dp.png')),
borderRadius: BorderRadius.circular(150)
),
),
SizedBox(width: SizeConfig.blockSizeHorizontal * 3,),
Flexible(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text('NAME', style: TextStyle(
fontFamily: 'myriadpro',
fontWeight: FontWeight.bold,
fontSize: SizeConfig.blockSizeVertical * 1.7
),),
SizedBox(height: SizeConfig.blockSizeVertical * 1,),
Text(lists[index]["text"],
maxLines: 20,
overflow: TextOverflow.clip,
style: TextStyle(
fontFamily: 'myriadpro',
fontSize: SizeConfig.blockSizeVertical * 1.7
),),
],
),
),
],
),
);
});
}
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
CircularProgressIndicator(valueColor: AlwaysStoppedAnimation(Colors.green),),
Text('Loading your posts... 🕑',
style: TextStyle(
fontFamily: 'myriadpro'
),
)
],
));
}),`