public class Person {
    private String name;
    private Boolean like;
    public Boolean getLike() {
        return like;
    }
    public void setLike(Boolean like) {
        this.like = like;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

@Named
@SessionScoped
public class PeopleModel {

    private List<Person> people;

    private Boolean liked;

    public List<Person> getPeople() {
        return people;
    }

    public void setPeople(List<Person> people) {
        this.people = people;
    }

    public Boolean getLiked() {
        return liked;
    }

    public void setLiked(Boolean liked) {
        this.liked = liked;
    }

}

@Named
@RequestScoped
public class PeopleController {

    @EJB
    PeopleRepositoryBean peopleRepo;

    @Inject
    PeopleModel model;

    @PostConstruct
    public void postConstruct(){
        init();
    }

    public void init(){
        Boolean liked = model.getLiked();

        // findPeopleILike(Boolean) method returns
        // -- only liked people when liked = true
        // -- only not liked people when liked = false
        // -- both when liked = null
        List<Person> people = peopleRepo.findPeopleILike(liked);
        model.setPeople(people);
    }
}