Steps to Add Dynamic Field in Product Create/Edit Form

<?php
namespace Mageplaza\CustomAttibute\Setup\Patch\Data;
use Magento\Catalog\Model\Product;
use Magento\Catalog\Model\Product\Type;
use Magento\ConfigurableProduct\Model\Product\Type\Configurable;
use Magento\Downloadable\Model\Product\Type as DownloadableType;
use Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface;
use Magento\Eav\Model\Entity\Attribute\Source\Boolean;
use Magento\Eav\Setup\EavSetup;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\Patch\DataPatchInterface;
use Magento\Framework\Setup\Patch\PatchRevertableInterface;
use Mageplaza\CustomAttibute\Model\Attribute\Backend\Pattern;
use Mageplaza\CustomAttibute\Model\Config\Source\CustomerGroups;


/**
* Class UpgradeProductAttr
* Mageplaza\CustomAttibute\Setup\Patch\Data
*/
class UpgradeProductAttr implements
   DataPatchInterface,
   PatchRevertableInterface
{
   /**
    * @var ModuleDataSetupInterface $moduleDataSetup
    */
   private $moduleDataSetup;


   /**
    * @var EavSetupFactory $eavSetupFactory
    */
   private $eavSetupFactory;


   /**
    * @var $savePattern
    */
   private $savePattern = Pattern::class;


   /**
    * @var $typeBoolean
    */
   private $typeBoolean = Boolean::class;


   /**
    * UpgradeProductAttr constructor.
    * @param ModuleDataSetupInterface $moduleDataSetup
    * @param EavSetupFactory $eavSetupFactory
    */
   public function __construct(
       ModuleDataSetupInterface $moduleDataSetup,
       eavSetupFactory $eavSetupFactory
   ) {
       $this->moduleDataSetup = $moduleDataSetup;
       $this->eavSetupFactory = $eavSetupFactory;
   }


   /**
    * Apply
    *
    * @return void
    * @throws \Magento\Framework\Exception\LocalizedException
    * @throws \Magento\Framework\Validator\ValidateException
    */
   public function apply()
   {
       $setup = $this->moduleDataSetup;
       /** @var EavSetup $eavSetup */
       $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);


       $eavSetup->addAttribute(
           Product::ENTITY,
           'mp_rw_customer_group',
           array_merge(
               $this->getDFOptionsProduct(),
               [
                   'type'    => 'text',
                   'backend' => $this->savePattern,
                   'label'   => 'Customer Group(s)',
                   'input'   => 'multiselect',
                   'class'   => 'mp_rw_customer_group',
                   'source'  => CustomerGroups::class,
                   'default' => null
               ]
           )
       );
   }


   /**
    * @return array
    */
   protected function getDFOptionsProduct()
   {
       $productTypes = [
           Type::TYPE_SIMPLE,
           Type::TYPE_VIRTUAL,
           DownloadableType::TYPE_DOWNLOADABLE,
           Configurable::TYPE_CODE
       ];


       return [
           'group'                   => 'Sell Product By Points',
           'global'                  => ScopedAttributeInterface::SCOPE_GLOBAL,
           'visible'                 => true,
           'required'                => false,
           'user_defined'            => false,
           'searchable'              => false,
           'filterable'              => false,
           'comparable'              => false,
           'visible_on_front'        => false,
           'used_in_product_listing' => true,
           'unique'                  => false,
           'frontend'                => '',
           'apply_to'                => join(',', $productTypes)
       ];
   }


   /**
    * @inheritdoc
    */
   public function revert()
   {
   }


   /**
    * @inheritdoc
    */
   public function getAliases()
   {
       return [];
   }


   /**
    * @inheritdoc
    */
   public static function getDependencies()
   {
       return [];
   }


   /**
    * @return string
    */
   public static function getVersion()
   {
       return '1.0.0';
   }
}

<?php

namespace Mageplaza\CustomAttibute\Model\Config\Source;
use Magento\Customer\Model\ResourceModel\Group\Collection;
use Magento\Eav\Model\Entity\Attribute\Source\AbstractSource;

/**
* Class CustomerGroups
* Mageplaza\CustomAttibute\Model\Config\Source
*/
class CustomerGroups extends AbstractSource
{
   /**
    * @var Collection
    */
   private $collection;


   /**
    * CustomerGroups constructor.
    *
    * @param Collection $collection
    */
   public function __construct(Collection $collection)
   {
       $this->collection = $collection;
   }

   /**
    * @return array
    */
   public function toOptionArray()
   {
       $this->_options[] = [
           'label' => __('-- Please Select --'),
           'value' => '999',
       ];


       foreach ($this->collection->toOptionArray() as $item) {
           $this->_options[] = [
               'label' => __($item['label']),
               'value' => $item['value'],
           ];
       }


       return $this->_options;
   }


   /**
    * Get all options
    *
    * @return array
    */
   public function getAllOptions()
   {
       $this->_options[] = [
           'label' => __('-- Please Select --'),
           'value' => '999',
       ];


       foreach ($this->collection->toOptionArray() as $item) {
           $this->_options[] = [
               'label' => __($item['label']),
               'value' => $item['value'],
           ];
       }


       return $this->_options;
   }
}