Hi Alex!

The option for linking posts of the same categories is only available for portfolio items (Customizer > Portfolio Options > Make Post Navigation Link All Categories). But for normal blog posts, I am afraid there is no option for that.

Anyway, you can easily customize the theme to add such feature. Please do:

1. Create a new child theme. You can find the how-to steps here: https://uxbarn.ticksy.com/article/8649/

2. In the "functions.php" file of the created child theme, add the following code:

function aina_print_post_navigation() {
        
        echo '<div class="next-prev-post-navigation content-width hover-style">';
            
            the_post_navigation( array(
                
                'prev_text' => '<span class="screen-reader-text">' . esc_html__( 'Previous Post', 'aina' ) . '</span><span aria-hidden="true" class="nav-subtitle">' . esc_html__( 'Previous', 'aina' ) . '</span> <span class="nav-title"><span class="nav-title-icon-wrapper"><i class="ion-ios-arrow-thin-left"></i></span>%title</span>',
                        
                'next_text' => '<span class="screen-reader-text">' . esc_html__( 'Next Post', 'aina' ) . '</span><span aria-hidden="true" class="nav-subtitle">' . esc_html__( 'Next', 'aina' ) . '</span><span class="nav-title">%title<span class="nav-title-icon-wrapper"><i class="ion-ios-arrow-thin-right"></i></span></span>',
                
                'in_same_term' => true,
            ) );
            
        echo '</div>';
            
    }

That's it. Now the blog post navigation should show only the posts that have the same categories.

I hope it helps.

Cheers,
Paul