Custom field not working on index.hbs

The post config option is strictly related to the post. It means that it will display, also on the homepage but for the post, it is assigned to.
So let’s see how it can work within the index.hbs file:

the loop displaying the posts listing with title and excerpt:

{{#each posts}}
   <article class="feed__item">
      <header>         
         <h2>
            <a href="{{url}}" >
               {{title}}
            </a>
         </h2>
      </header>   
      <p>
        {{{ excerpt }}}
      </p>
   </article>
{{/each}}

now let’s add the contents of the subTitle field between the title and excerpt section using the postViewConfig object.

{{#each posts}}
   <article class="feed__item">
      <header>         
         <h2>
            <a href="{{url}}" >
               {{title}}
            </a>
         </h2>
      </header>
      <p> 
        {{postViewConfig.subTitle}}
      </p>   
      <p>
        {{{ excerpt }}}
      </p>
   </article>
{{/each}}

As a result, the subTitle will be displayed only for the post where you fill in the content of the subTitle field.

For example, if the loop displays five posts and you fill in the subTitle field for only one of them, for example Post-X, then the subTitle will only be displayed once in the loop in place of Post-X.
The rest of the posts in the loop will show an empty paragraph – to avoid it you can use the “if” statement:

{{#if postViewConfig.subTitle}}
   <p>{{postViewConfig.subTitle}} </p>
{{/if}}