You can use the following code to list the posts that are categorized under category id 3 OR have tag ‘urgent’
function exclude_category($query) {
if ( $query->is_home ) {
$query->set( 'tax_query', array(
'relation' => 'OR',
array(
'taxonomy' => 'category',
'field' => 'ID',
'terms' => 3
),
array(
'taxonomy' => 'post_tag',
'field' => 'slug',
'terms' => 'urgent'
)
));
}
return $query;
}
add_filter('pre_get_posts', 'exclude_category');