How to add condition to business object

Summary:

How to add conditions to a new business object (Position)?

Content (please ensure you mask any confidential information):

Need to fetch HCM positions with two conditions:

1. Position belongs to user department (organisation)
2. Position has not been end dates.
3. how to add a limitation - by default it returns 25 names, how I can limit to 5?

Would much appreciate your help how to achieve the above conditions.

Thanks.

Version (include the version you are using, if applicable):

25C

Code Snippet (add any code snippets that support your topic, if applicable):