Change related blog section

functions.php

@@ -19,3 +19,33 @@ function my_acf_google_map_api( $api ){
 }
 
 add_filter('acf/fields/google_map/api', 'my_acf_google_map_api');
+
+// Related posts function
+function atravelblog_related_posts() {
+
+	echo('<div class="related-posts posts section-inner">');
+	global $post;
+	if ( get_the_category()[0]->name == 'Urlaub' ){
+		$tagebuch = get_posts(array(
+			'category_name' => 'Tagebuch'
+		));
+
+		if ($tagebuch->have_posts()) :
+			while ( $tagebuch->have_posts() ) : $tagebuch->the_post(); ?>
+
+				<?php global $post; ?>
+
+				<?php get_template_part( 'content', get_post_format() ); ?>
+
+			<?php endwhile; ?>
+		<?php endif; ?>
+
+		<div class="clear"></div>
+
+		<?php wp_reset_query(); ?>
+
+		</div> <!-- /related-posts --> <?php
+
+	}
+
+}