bp_get_attachment_document_id( integer $attachment_id )

function bp_get_attachment_document_id( $attachment_id = 0 ) {
	global $bp, $wpdb;

	if ( ! $attachment_id ) {
		return false;
	}

	// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery
	$attachment_document_id = (int) $wpdb->get_var( "SELECT DISTINCT d.id FROM {$bp->document->table_name} d WHERE d.attachment_id = {$attachment_id}" );

	return $attachment_document_id;
}