Hi Boris

I’m afraid this is not possible…

I had another user try to implement this, and their workaround was to create a custom taxonomy and manually assign their posts to taxonomy terms like A, B, C etc.

There could be a way to automate this, which is to automatically add your posts (when they are saved/published) to the correct taxonomy terms – but this would be some custom code.

I can point you in the right direction – this seems like a good starting point:

http://wordpress.stackexchange.com/questions/126409/automatically-assign-taxonomy-term-if-custom-meta-value-exists

I guess you would check the starting letter of the post title, and assign taxonomy based on that.

I hope that helps.

Thanks

From the documentation (I think this is what you want):

Customising the Results

If you wish to customise the display of your results, you must override the default template that is being used by Search & Filter:

Create a folder in your theme folder called search-filter.
Copy the file wp-content\plugins\search-filter\templates\results.php from the templates folder in to the newly created folder in your theme – wp-content\themes\your-theme-name\search-filter\results.php

From now on, Search & Filter will load this version of the template instead of its own – so you can make any customisations that are necessary.

Ah. If you edit the results.php file that you copied to your (child) theme folder, you will find this code in the middle of it (I have edited it a bit to compress it, but it looks somewhat like this):

<?php
while ($query->have_posts())
  {
    $query->the_post();
?>
<?php /* echo get_post_mime_type(get_the_ID()); */ ?>
<div>
  <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
  <p><br /><?php the_excerpt(); ?><p>
<?php 
if ( has_post_thumbnail() ) {
  echo '<p>';
  the_post_thumbnail("small");
  echo '</p>';
}
?>
  <p><?php the_category(); ?><p>
  <p><?php the_tags(); ?><p>
  <p><small><?php the_date(); ?></small><p>
</div>
<hr />
<?php
}
?>

Try replacing that with this:

<ul class="custom-sf-results-list">
<?php
while ($query->have_posts())
  {
    $query->the_post();
?>
<?php /* echo get_post_mime_type(get_the_ID()); */ ?>
<li><div>
  <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
  <p><br /><?php the_excerpt(); ?><p>
<?php 
if ( has_post_thumbnail() ) {
  echo '<p>';
  the_post_thumbnail("small");
  echo '</p>';
}
?>
  <p><?php the_category(); ?><p>
  <p><?php the_tags(); ?><p>
  <p><small><?php the_date(); ?></small><p>
</div></li>
<hr />
<?php
}
?>
</ul>

Not sure if that will work.