Get all users with a given claim

I'm working on an aspnet core 1.0 project, I've recently understood what claims are and how to use them to achieve policy based authorization.

What I'm trying to acheive:

I want to get all users that are authorized with a given policy (i.e. users that have a given claim, let's say Claim {Type = "CanReceiveXReport", Value = True})

The code I'd expect to do this is something like:

public static IQueryable<User> WithClaim(this IQueryable<User> users, string claimName) =>
    users
        .Include(u=> u.Claims)
        .Where(u=> u.Claims.Any(c=> c.ClaimType == claimName));

The problem:

When I run the above code, for all users, user.Claims is always empty. I've also tried to materialize the query by adding a ToList() after the Include() with no success.

When I realized this wasn't working I expected there to be a ClaimsManager<T> of some sort to do this kind of operations.

All the apis and answers I've found are focused on getting claims for a single user.

I know I could do something like what this answer but I rather not do that, I want that query to be run in the database.

I imagine it's possible to create a stored procedure, but I'd rather mantain my domain logic in my app.

Versions:

(That I think are relevant)

{
    "Microsoft.AspNetCore.Identity": "1.0.0",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0",
    "Microsoft.EntityFrameworkCore.Relational": "1.0.0",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.1",
    "Microsoft.NETCore.App": "1.0.0"
}