public class TestEntity {
    public Long testId;

    @Column(name = "test_id")
    @Id
    public Long getTestId() {
        return testId;
    }

    public void setTestId(Long testId) {
        this.testId = testId;
    }

    private CollectionType custom;

    @Formula(value = "fa.GET_REASONS_NAMES(test_id)")
    @Type(type = "ru.esoft.Platform.hibernatetools.CollectionTypeDescriptor",
            parameters = @org.hibernate.annotations.Parameter(name = "columns", value = "String name"))
    @Basic(fetch = FetchType.LAZY, optional = true)
    @LazyToOne(value = LazyToOneOption.FALSE)
    public CollectionType getCustom() {
        return custom;
    }

    public void setCustom(CollectionType custom) {
        this.custom = custom;
    }
}

List list = session.createCriteria(TestEntity.class, "this").
                    setFetchMode("this.custom", FetchMode.JOIN). // fetch me custom please
                    add(Restrictions.idEq(489281L)).list();
            for (Object o : list)
                System.out.println(((TestEntity)o).getCustom());

Hibernate:
    select
        this_.test_id as test1_0_0_
    from
        instr_test this_
    where
        this_.test_id = ?
Hibernate:
    select
        fa.GET_REASONS_NAMES(testentity_.test_id) as formula0_
    from
        instr_test testentity_
    where
        testentity_.test_id=?
489281-10-0005, 489281-10-0004

List list = session.createCriteria(TestEntity.class, "this").
                    setProjection(Projections.projectionList().
                            add(Projections.property("id")).
                            add(Projections.property("custom"))).
                    setFetchMode("this.custom", FetchMode.JOIN).
                    add(Restrictions.idEq(489281L)).list();