To keep things simple just restructure the model:
$scope.messages = [
[
{
"network": "twitter",
...
},
{
"network": "facebook",
...
}
],
[
{
"network": "twitter",
...
},
{
"network": "facebook",
...
}
]
]
HTML:
<table>
<tr ng-repeat="message in messages" >
<td ng-repeat="msg in message">
<div ng-if="msg.network == 'twitter'">
<div ng-controller="TweetController">
...
<span>{{msg.createdAt}}</span>
<span>{{msg.network}}</span>
<span>{{msg.text}}</span>
</div>
</div>
<div ng-if="msg.network == 'facebook'">
<div ng-controller="FacebookController">
...
<span>{{msg.createdAt}}</span>
<span>{{msg.network}}</span>
<span>{{msg.text}}</span>
</div>
</div>
</td>
</tr>
</table>