bp_document_delete_activity_document( $activities )

function bp_document_delete_activity_document( $activities ) {
	if ( ! empty( $activities ) ) {
		remove_action( 'bp_activity_after_delete', 'bp_document_delete_activity_document' );
		foreach ( $activities as $activity ) {
			$activity_id       = $activity->id;
			$document_activity = bp_activity_get_meta( $activity_id, 'bp_document_activity', true );
			if ( ! empty( $document_activity ) && '1' == $document_activity ) {
				bp_document_delete( array( 'activity_id' => $activity_id ) );
			}

			// get document ids attached to activity.
			$document_ids = bp_activity_get_meta( $activity_id, 'bp_document_ids', true );
			if ( ! empty( $document_ids ) ) {
				$document_ids = explode( ',', $document_ids );
				foreach ( $document_ids as $document_id ) {
					bp_document_delete( array( 'id' => $document_id ) );
				}
			}
		}
		add_action( 'bp_activity_after_delete', 'bp_document_delete_activity_document' );
	}
}