Shared fields

fields.php

function sponsor_fields(){

      $sponsor_id = '';

      if( isset( $_GET['post'] ) ){
        $sponsor_id = get_post_meta( $_GET['post'], '_os_sponsor_id', true );
      } else if( isset( $_GET['taxonomy'] ) ){
        $sponsor_id = get_term_meta( $_GET['tag_ID'], '_os_sponsor_id', true );
      } else {
        return;
      }
      
      $prefix = '_os_sponsor_';

      $post_types = get_post_types();

      unset($post_types['nav_menu_item']);
      unset($post_types['attachment']);
      unset($post_types['revision']);

      $sponsored_post_types = array();

      foreach($post_types as $key => $value){
        $sponsored_post_types[] = $value;
      }

      $sponsor_id_field = array(
        'name' => 'Select Sponsor',
        'id'	=> $prefix . 'id',
        'type' => 'select',
        'show_option_none' => true,
        'options' => array(),
        'attributes' => array(
          'data-value' => $sponsor_id
        )
      );

      $sponsor_link = array(
        'name'       => __( 'Sponsor Link', 'cmb2' ),
        'id'         => $prefix . 'sponsor_link',
        'type'       => 'text_url'
      );

      $post_types_cmb = new_cmb2_box( array(
        'id'            => 'os_sponsor_meta',
        'title'         => __( 'OS Sponsor Data', 'cmb2' ),
        'object_types'  => $sponsored_post_types, // Post type
        'context'       => 'normal',
        'priority'      => 'high',
        'show_names'    => true
      ) );

      $post_types_cmb->add_field( $sponsor_id_field );
      $post_types_cmb->add_field( $sponsor_link );
      

      $taxonomy_cmb = new_cmb2_box( array(
        'id'            => 'os_sponsor_tax_meta',
        'object_types'  => array( 'term' ), // Tells CMB2 to use term_meta vs post_meta
        'taxonomies'    => array( 'series' ),
        'context'       => 'normal',
        'priority'      => 'high',
        'show_names'    => true
      ) );

      $taxonomy_cmb->add_field( $sponsor_id_field );
      $taxonomy_cmb->add_field( $sponsor_link );

      

    }

  }