You would need something like this:
add_filter('request', function( array $query_vars ) {
if ( is_admin() ) {
return $query_vars;
}
$targets = array(
'my-category-slug',
'my-category-slug-2',
'my-category-slug-3',
);
if ( isset( $query_vars['category_name'] ) && in_array( $query_vars['category_name'], $targets ) ) {
$pagename = $query_vars['category_name'];
$query_vars = array( 'pagename' => "$pagename" );
}
return $query_vars;
} );
Kindly replace my-category-slug, my-category-slug-2, my-category-slug-3 with the slugs, and you may also add more if necessary.
Hope this helps!