Hi Stiofan,
Thanks for the code, but it doesn’t seem to do anything. Neither using the default category or specifying a specific category.
I notice you are using “geodir_related_posts_widget_query_args”
The Related Listing I’m talking about is the one that displays at the bottom of the details page,
Design > Detail > Related Post Settings
Not the one you setup using a widget. Is there a different filter for the area I’m talking about?
Here’s the code that doesn’t work, the original was missing a “)”
add_filter('geodir_related_posts_widget_query_args','_my_gd_related_filter',10,2);
function _my_gd_related_filter($query_args, $request){
    
    if(isset($query_args['tax_query']['terms'])){
        global $post;
        $query_args['tax_query']['terms'] = array($post->default_category);
    }
    return $query_args;
}
Thanks