User Entities used in the seeded Extracts are not available to use in newly custom created extracts

I am creating a Payroll Costing related HCM Extract. I referred the oracle seeded HCM extracts, there is one named 'Payroll Costing Report', this extract has all my required details. I am want to use the user entities which are used in the seeded extract. But the problem is that, when i am creating new extract, and trying to add the those user entities, It is not allowing me to use those UEs. If I search for those user entities, I can see them in the View User Entity Section. But I am not able to get the UEs inside