Custom gender field and filter in member directory for it

functions.php

function custom_um_query_args_c2n_gender__filter_meta( $skip, $query, $field, $value, $filter_type, $is_default ) {
	if ( ! is_array( $value ) ) {
		$value = array( $value );
	}

	// $join_alias is pre-escaped.
	$query->joins[] = "LEFT JOIN {$wpdb->prefix}um_metadata {$join_alias} ON {$join_alias}.user_id = u.ID";

	$values_array = array();
	foreach ( $value as $single_val ) {
		$single_val = trim( stripslashes( $single_val ) );

		// phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $join_alias and $compare variables are pre-escaped.
		$values_array[] = $wpdb->prepare( "{$join_alias}.um_value LIKE %s", '%"' . $wpdb->esc_like( $single_val ) . '"%' );
		$values_array[] = $wpdb->prepare( "{$join_alias}.um_value = %s", $single_val );
		// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $join_alias is pre-escaped.
	}

	$values = implode( ' OR ', $values_array );

	// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $join_alias and $values variables are pre-escaped or $wpdb->prepare.
	$query->where_clauses[] = $wpdb->prepare( "( {$join_alias}.um_key = %s AND ( {$values} ) )", $field );

	if ( ! $is_default ) {
		$query->custom_filters_in_query[ $field ] = $value;
	}
	return true;
}
add_filter( 'um_query_args_c2n_gender__filter_meta', 'custom_um_query_args_c2n_gender__filter_meta', 10, 6 );

function custom_um_query_args_c2n_gender__filter( $query, $field, $value, $filter_type ) {
	if ( ! is_array( $value ) ) {
		$value = array( $value );
	}

	if ( is_array( $value ) ) {
		$field_query = array( 'relation' => 'OR' );

		foreach ( $value as $single_val ) {
			$single_val = trim( stripslashes( $single_val ) );

			$arr_meta_query = array(
				array(
					'key'     => $field,
					'value'   => $single_val,
					'compare' => '=',
				),
				array(
					'key'     => $field,
					'value'   => '"' . $single_val . '"',
					'compare' => 'LIKE',
				),
			);

			$field_query = array_merge( $field_query, $arr_meta_query );
		}
	}

	if ( ! empty( $field_query ) ) {
		UM()->member_directory()->query_args['meta_query'] = array_merge( UM()->member_directory()->query_args['meta_query'], array( $field_query ) );

		UM()->member_directory()->custom_filters_in_query[ $field ] = $value;
	}
	return true;
}
add_filter( 'um_query_args_c2n_gender__filter', 'custom_um_query_args_c2n_gender__filter', 10, 4 );