ユーザーごとにenum型の登録値を合計して、ショートコードに一覧化するフィルターフックおよび集計関数の例。 デモはこちら -> http://demo.ka2.org/narrow-by-sum/

enum_aggregate.php

<?php
/**
 * Function to aggregate the value of the enum type
 * 
 * @param string $target_table [requied]
 * @param string $userid_col [requied]
 * @param string $enum_col [required]
 * @param string $period [optional] It must be a target date string, ex."2016-06-23"
 */
function enum_aggregate( $target_table, $userid_col, $enum_col, $period=null ) {
  global $cdbt;
  if ( is_object( $cdbt ) && $cdbt->check_table_exists( $target_table ) ) {
  	$_schema = $cdbt->get_table_schema( $target_table );
    $_enum_values = isset( $_schema[$enum_col] ) && preg_match('/^enum\(\'(.*)\'\)$/i', $_schema[$enum_col]['type_format'], $matchies ) ? explode( "','", $matchies[1] ) : [];
    if ( empty( $_enum_values ) ) return;
    $_data = $cdbt->run_query( sprintf( 'SELECT `%s` FROM `%s` GROUP BY `%s`', $userid_col, $target_table, $userid_col ), 'PDO' );
	$_where_date = ! empty( $period ) ? sprintf( "AND `created` BETWEEN '%s 00:00:00' AND '%s 23:59:59'", $period, $period ) : '';
    foreach ( $_data as $_i => $_row ) {
      $_sum_col = 0;
      foreach ( $_enum_values as $_val ) {
        $_res = $cdbt->run_query( sprintf( "SELECT COUNT(*) FROM `%s` WHERE `%s`='%s' AND `%s`='%s' %s", $target_table, $userid_col, $_row[$userid_col], $enum_col, $_val, $_where_date ), 'PDO' );
        $_data[$_i][$_val] = intval( $_res['COUNT(*)'] );
        $_sum_col += intval( $_res['COUNT(*)'] );
      }
      $_data[$_i]['total'] = $_sum_col;
    }
    $_sum_row = $_data[0];
    $_sum_row[$userid_col] = 'total';
    $_sum_col = 0;
    foreach ( $_enum_values as $_i => $_val ) {
      $_sum_row[$_val] = 0;
      foreach ( $_data as $_row ) {
        $_sum_row[$_val] += $_row[$_val];
        $_sum_col += $_row[$_val];
      }
    }
    $_sum_row['total'] = $_sum_col;
    $_data[] = $_sum_row;
  } else {
    $_data = false;
  }
  return $_data;
}

function render_enum_aggregate( $component_options, $shortcode_name, $table ) {
  if ( ! is_admin() && 'your_target_table' === $table ) {
    $component_options['data'] = enum_aggregate( 'your_target_table', 'userid_column', 'enum_column', '2016-06-23' );
  }
  return $component_options;
}
add_filter( 'cdbt_shortcode_custom_component_options', 'render_enum_aggregate', 10, 3 );

function custom_enum_aggregate_columns( $columns, $shortcode_name, $table ) {
  if ( ! is_admin() && 'your_target_table' === $table ) {
    // Exclude columns
    foreach ( $columns as $_i => $_column ) {
      $_custom_column = '';
      switch( $_column['property'] ) {
      	case 'ID':
        case 'enum_column':
        case 'created':
        case 'updated':
          unset( $columns[$_i] );
          break;
      }
    }
    // Add new columns
    global $cdbt;
  	$_schema = $cdbt->get_table_schema( $table );
  	$enum_col = 'enum_column';
  	$_new_cols = [];
    $_enum_values = isset( $_schema[$enum_col] ) && preg_match('/^enum\(\'(.*)\'\)$/i', $_schema[$enum_col]['type_format'], $matchies ) ? explode( "','", $matchies[1] ) : [];
    $_new_cols = array_merge( $_new_cols, $_enum_values, [ 'total' ] );
    foreach ( $_new_cols as $_val ){
      $columns = array_merge( $columns, [ [ 
        'label' => $_val, 
        'property' => $_val, 
        'sortable' => true, 
        'sortDirection' => 'asc', 
        'dataNumric' => true, 
        'truncateStrings' => '0', 
        'className' => '', 
      ] ] );
    }
  }
  return $columns;
}
add_filter( 'cdbt_shortcode_custom_columns', 'custom_enum_aggregate_columns', 10, 3 );

/**
 * I tested table structure below, then worked correctly.
 *

CREATE TABLE `sum_enum` (
  `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT 'ID',
  `user_id` varchar(10) NOT NULL DEFAULT '0',
  `category` enum('aaa','bbb','ccc','ddd','eee') NOT NULL DEFAULT 'aaa',
  `created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT 'Created Datetime',
  `updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'Updated Datetime',
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

*/

Also, it's placing of search field to frontend as post content.

<form method="get" class="form-inline" style="margin-bottom: .5em;">
  <div class="input-group">
    <input type="search" name="period" class="form-control" placeholder="Narrow by date">
    <span class="input-group-btn"><button type="submit" class="btn btn-default">Narrow Down</button></span>
  </div>
</form>
[cdbt-view table="your_table_name" display_search="false" display_title="false" display_index_row="head-only" footer_interface="pager" sort_order="grouping_column_name:asc"]