How to use two titles in Ionic header?

In ionic, I need to use 'Heading'(Large one) and 'Sub-heading'(smaller one). I am using like following,

<ion-view view-title="Primary Heading">
    <ion-content>.....</ion-content>
</ion-view>

This is working. But, I need to use two headings. One as 'Primary heading' and another one as 'Sub-heading'. I tried to use 'header-bar', 'sub-header-bar'. But, it is not working as I expected. Heading should be in first line and sub-heading should be in next line. I also tried with 

 <ion-nav-title>...</ion-nav-title>

So, how to achieve this one. And also I have to apply my own styling for Headings. Please, help me out.

I think you are looking for a tab solution with subheader. The first header is set by the <ion-view> as you mentioned. The subheader can be set with <ion-header>.

<ion-view title="Primary Heading">
    <ion-header-bar class="bar bar-subheader">
        <h1 class="title">Subheader</h1>
    </ion-header-bar>
    <ion-content>
        CONTENT
    </ion-content>
</ion-view>

See next CodePen: http://codepen.io/calendee/pen/keHnw

After trying out, My answer for my question is, 

 <ion-view> 
    <ion-nav-title>
        <div class="page-title">HEADING</div>
        <div class="page-sub-title">Sub Heading</div>
    </ion-nav-title>
    <ion-content>.....</ion-content>
</ion-view>

And to apply style, my CSS would be like this,

.page-title{
         margin-top : -10px;
         color: #ffffff;
         font-size: 1.5em;
}
.page-sub-title{
         margin-top: - 25px;
         color: green;
         font-size : .9em;
}