I'm using CMB2 plugin to add metaboxes into a custom post type. I'm adding the additional metaboxes via functions.php onto child theme. It may worth to mention that parent theme/custom post already has a few metaboxes defined, I'm just complementing...

I already successfully created metaboxes with field type = Text and echo values into target page, however when filed type = Select I can create the meta field but can't echo the selected option into target page.

Could you please help me out? I appreciate it.

Functions.php (creating the metaboxes)

add_action( 'cmb2_meta_boxes', 'custom_metabox' );

function custom_metabox( array $metaboxes ) {
    $metaboxes[REALIA_PROPERTY_PREFIX . 'ficha_tecnica'] = array(
        'id'                        => REALIA_PROPERTY_PREFIX . 'ficha',
        'title'                     => 'Ficha Técnica',
        'object_types'              => array( 'property' ),
        'context'                   => 'normal',
        'priority'                  => 'high',
        'show_names'                => true,
        'fields'                    => array(
         
            array(
                'id'    => REALIA_PROPERTY_PREFIX . 'area_terreno',
                'name'  => 'Área do Terreno',
                'type'  => 'text'
            ),
        
            array(
                'id'               => 'wiki_test_select',
                'name'             => 'Test select inline',
                'type'             => 'select',
                'show_option_none' => true,
                'default'          => 'custom',
                'options'          => array(
                    'standard' => __( 'test123', 'ficha' ),
                    'custom'   => __( 'test1234', 'ficha' ),
                     'none'     => __( 'test12345', 'ficha' ),
            ),
        ),
    ),
);

return $metaboxes;

}

And then I output onto the page's content area

    <div class="col-sm-12 <?php if ( ! empty( $images ) ) : ?>col-md-5<?php else : ?>col-md-12<?php endif; ?>">
    <div class="property-list">
        <h2><?php echo __( 'Property overview', 'realia' ); ?></h2>

        <dl>
            <?php $price = Realia_Price::get_property_price(); ?>
            <?php if ( ! empty( $price ) ) : ?>
                <dt><?php echo __( 'Price', 'realia' )?></dt><dd><?php echo wp_kses( $price, wp_kses_allowed_html( 'post' ) ); ?></dd>
            <?php endif; ?>

            <?php $area = get_post_meta( get_the_ID(), REALIA_PROPERTY_PREFIX . 'attributes_area', true ); ?>
            <?php if ( ! empty( $area ) ) : ?>
                <dt><?php echo __( 'Área do Terreno', 'realia' ); ?></dt><dd><?php echo esc_attr( $area ); ?> <?php echo get_theme_mod( 'realia_measurement_area_unit', 'sqft' ); ?></dd>
            <?php endif; ?>
            
            <?php $metafield_id = get_the_ID(); ?>
            <?php $test = get_post_meta( $metafield_id, REALIA_PROPERTY_PREFIX . 'options', true ); ?>
            <?php if ( ! empty( $test ) ) : ?>
                <dt><?php echo __( 'test123', 'realia' ); ?></dt><dd><?php echo $test; ?></dd>
            <?php endif; ?>

        </dl>
    </div><!-- /.property-list -->
</div>

<h2 class="page-header"><?php echo __( 'Apresentação', 'realia' ); ?></h2>

<div class="property-detail-description">
    <?php the_content(); ?>
</div><!-- /.property-detail-description -->