gistfile1.txt

add_filter( "houzez_property_feed_properties_due_import_alto", 'specific_firmid', 10, 2 );
function specific_firmid( $properties, $import_id )
{
    $new_properties = array();
    
    foreach ( $properties as $property )
    {
        $property_attributes = $property->attributes();
        
        if ( (string)$property_attributes['firmid'] == '38942' )
        {
            $new_properties[] = $property;
        }
    }
    
    return $new_properties;
}