JPA Criteria 2 embebbed JOINs and condition between them - sql

Question

I'm gonna adapt my problem to a simple example. Lets say I have 2 entities: Employee and EmployeeCompany (the class that defines the relation of a Employee with a Company).
I need to retrieve the Employee entities that are associated with 2 EmployeeCompany entities, and these 2 EmployeeCompany entities must share the same value for a specific attribute (let's call this attribute "X"). EmployeeCompany entities have also embebbed identifiers, so the entities definition would look something like this:
Employee:
Long idEmployee;
List<EmployeeCompany> employeeCompanies;
EmployeeCompany:
// Embebbed ID
EmployeeCompanyId id;
Long X;
EmployeeCompanyId:
Long idEmployee;
Long idCompany;
This is what I'm currently doing to make the 2 JOINs with the EmployeeCompany tables starting from the Employee entity:
Root<T> root = criteria.from(Employee.class);
Join<Object, Object> joinFirstEmployeeCompanyId = root.join("employeeCompanies").join("id");
Predicate finalPredicate = builder.equal(joinFirstEmployeeCompanyId.get("idCompany"), idCompany1);
Join<Object, Object> joinSecondEmployeeCompanyId = root.join("employeeCompanies").join("id");
finalPredicate = builder.and(finalPredicate, builder.equal(joinSecondEmployeeCompanyId.get("idCompany"), idCompany2));
My problem is, I don't know how I can specify now that between these 2 joins, they must meet the X attribute condition (both EmployeeCompany entities must have the same value for the X attribute).
In case it helps, this is what the SQL query would look like:
SELECT * FROM Employee e
INNER JOIN EmployeeCompany ec1 ON ec1.idemployee = e.idemployee AND ec1.idcompany = :idCompany1
INNER JOIN EmployeeCompany ec2 ON ec2.idemployee = e.idemployee AND ec2.idcompany = :idCompany2
WHERE c1.X = c2.X

Answer 1

I solved my issue this way:
Root<T> root = criteria.from(Employee.class);
Join<Object, Object> joinFirstEmployeeCompany = root.join("employeeCompanies");
joinFirstEmployeeCompany.on(builder.equal(joinFirstEmployeeCompany.get("id").get("idCompany"), idCompany1));
Join<Object, Object> joinSecondEmployeeCompany = root.join("employeeCompanies");
joinSecondEmployeeCompany.on(builder.equal(joinSecondEmployeeCompany.get("id").get("idCompany"), idCompany2));
Predicate finalPredicate = builder.equal(joinFirstEmployeeCompany.get("X"), joinSecondEmployeeCompany.get("X"));