foreign key not getting copied to level 4 + jpa + hibernate - spring-boot

Question

My Entity level is like this
Level One
#Entity
public class LevelOne {
#Id
private long levelOnePK;
#OneToMany(mappedBy = "levelOne")
private Set<LevelTwo> levelTwo;
//getters setters omitted
}
Level Two
#Entity
public class LevelTwo {
#Id
private long levelTwoPK;
#ManyToOne
#JoinColumn(name = "levelOnePK")
private LevelOne levelOne;
#OneToMany(mappedBy = "levelTwo")
private Set<LevelThree> levelThree;
//getters setters omitted
}
Level Three
#Entity
public class LevelThree {
#Id
private long levelThreePK;
#ManyToOne
#JoinColumn(name = "levelOnePK")
#JoinColumn(name = "levelTwoPK")
private LevelTwo levelTwo;
#OneToMany(mappedBy = "levelThree")
private Set<LevelFour> levelFour;
//getters setters omitted
}
Level Four // Not working. Why ??
#Entity
public class LevelFour {
#Id
private long levelFourPK;
#ManyToOne
#JoinColumn(name = "levelOnePK")
#JoinColumn(name = "levelTwoPK")
#JoinColumn(name = "levelThreePK")
private levelThree levelThree;
//getters setters omitted
}
For the fourth level the error is "It is not mapped to a single entity"
It works upto level 3 and does not at level 4. I want the primary / foreign key of every level go down to the level below. I am joining using all the primary keys from the above tables but it does not work.
It works if i join only if I do the below in Level 4. But i want keys from above level as well.
#ManyToOne
#JoinColumn(name = "levelThreePK")
private levelThree levelThree;