The default Magento 2 offers the rule tree condition field using which the admin can configure the condition-based features.
For example, the admin may want to offer a discount coupon only on certain products or specific customer groups.
As online stores grow complex, the condition-based features are used more. Additionally, if you are customizing your own features for a better shopping platform, you may need to add rule condition field in Magento 2 admin UI component form as shown below.

You can do so with the below code.
Method to Add Rule Condition Field in Magento 2 Admin UI Component Form:
Create [Vendor]/[Module]/view/adminhtml/layout/route_controller_grid.xml
<fieldset name="conditions"> <argument name="data" xsi:type="array"> <item name="config" xsi:type="array"> <item name="label" xsi:type="string" translate="true">Conditions</item> <item name="collapsible" xsi:type="boolean">true</item> <item name="sortOrder" xsi:type="number">10</item> </item> </argument> <container name="conditions" > <argument name="data" xsi:type="array"> <item name="config" xsi:type="array"> <item name="sortOrder" xsi:type="number">10</item> </item> </argument> <htmlContent name="html_content"> <argument name="block" xsi:type="object">Magento\SalesRule\Block\Adminhtml\Promo\Quote\Edit\Tab\Conditions</argument> </htmlContent> </container> </fieldset>
That’s it. Also you can Magento 2 custom attribute validation rule using ruleFactory enhances e-commerce customization and efficiency, allowing dynamic promotions and improving the user experience.
Also read: How to Validate Condition Rules in Custom Module in Magento 2.
I’d be happy to help.
Also, do share the solution with Magento Community via social media.
Thank you.