Referencing to the original post on CRM 2013 from here.
As Business Rules are created for a particular entity, we can see all the business rules that have been created for any particular entity from the entity customization itself.
This is ok when we need to see all the business rules on an entity. But it does not allow us to pull up a list of business rules across the whole system. Sometimes after deploying a solution, we need to check the business rules to make sure they’re activated, or if there are any errors, and we don’t want to have to go through each entity and check these.
As Business Rules are workflows under the hood, we can do an Advanced Find query with filter criteria on Categories as Business Rule (for CRM 2013, it was PBL) to get the list of all business rules in an organization. The result contains Name, Primary Entity, status and other basic information about the business rule.