Add custom dimensions to admin list and frontend values

monsterinsights-add-custom-dimensions-via-filter.php

/**
 * This would add custom dimension to the admin list inside settings.
 */
function monsterinsights_add_dimensions_to_admin_list( $dimensions ) {

	// Add dimension to array with a unique key 'services'
	$dimensions['services'] = array(
		'title'   => __( 'Services', 'monsterinsights-dimensions' ), // Label
		'label'   => __( 'Services', 'monsterinsights-dimensions' ), // Description
		'enabled' => true,
		'metric'  => 'sessions',
	);

	$dimensions['project'] = array(
		'title'   => __( 'Project', 'monsterinsights-dimensions' ),
		'label'   => __( 'Project', 'monsterinsights-dimensions' ),
		'enabled' => true,
		'metric'  => 'sessions',
	);

	return $dimensions;
}
add_filter('monsterinsights_available_custom_dimensions', 'monsterinsights_add_dimensions_to_admin_list');

/**
 * This would add the value of custom dimensions added above.
 */
function monsterinsights_custom_add_dimensions_value( $options ) {

	$post_type = '';

	if ( is_singular() ) {
		$post_type = get_post_type( get_the_ID() );
	}

	if ( '' === $post_type ) {
		return;
	}

	$dimensions = monsterinsights_get_option( 'custom_dimensions', array() );

	if ( ! empty( $dimensions ) && is_array( $dimensions ) ) {
		// Sort by array key `id` value
		$id = array();
		foreach ( $dimensions as $key => $row ) {
			if ( empty( $row['type'] ) || empty( $row['id'] ) ) {
				unset( $dimensions[ $key ] );
				continue;
			}
			$id[ $key ] = $row['id'];
		}
		array_multisort( $id, SORT_ASC, $dimensions );

		foreach ( $dimensions as $dimension ) {
			if ( empty( $dimension['type'] ) || empty( $dimension['id'] ) ) {
				continue;
			}
			$type  = $dimension['type'];
			$id    = $dimension['id'];
			$value = '';
			switch ( $type ) {
				case 'services':
					$value = $post_type; //Get whatever value we need to send in the dimension;
					break;
				case 'project':
					$value = $post_type; //Get whatever value we need to send in the dimension;
					break;
			}

			if ( ! empty( $value ) ) {
				$options[ 'dimension' . $id ] = "'set', 'dimension" . absint( $id ) . "', '" . esc_js( addslashes( $value ) ) . "'";
			}
		}
	}

	return $options;
}
add_filter( 'monsterinsights_frontend_tracking_options_persistent_gtag_before_pageview', 'monsterinsights_custom_add_dimensions_value', 20 );