Hi tactics
At this momemt you can only show one or the other. You can use a workaround by adding the excerpt to the post title with this filter:
https://keesiemeijer.wordpress.com/related-posts-by-taxonomy/filters/#related_posts_by_taxonomy_caption
[edit] This works with the current version of the plugin 2.0.1
Try it with this in your (child) theme’s functions.php
add_filter( 'related_posts_by_taxonomy_caption', 'rpbt_add_excerpt_to_caption', 10, 2 );
function rpbt_add_excerpt_to_caption( $caption, $_post ) {
global $post;
$post = $_post;
// the title
$caption = '<h3>' . $caption . '</h3>';
// the excerpt
setup_postdata( $_post );
$caption .= apply_filters( 'the_excerpt', get_the_excerpt() );
// reset global $post object
wp_reset_postdata();
return $caption;
}
btw:
consider creating a child theme instead of editing your theme directly – if you upgrade the theme all your modifications will be lost. Or create a plugin with the code above.