1. Create a segmentation or automation rule.
2. Select Prospect Opportunity as a criteria.
3. From the Match Prospects dropdown, select related with properties.
4. In the section that appears, select Prospect opportunity customfield from the first dropdown.
5. From the second dropdown, select your custom field.
6. Choose an operator.
7. Enter or select the value you want to match.
8. Finish creating your rule.