Nhibernate projection with alias to nested property - nhibernate

Question

I have a DTO class like this:
public class Aggregates
{
public Aggregates()
{
Sales = new StatisticAggregates();
Refund = new StatisticAggregates();
}
public int ChecksAmount { get; set; }
public StatisticAggregates Sales { get; set; }
public StatisticAggregates Refund { get; set; }
public int TotalAmount { get { return Sales.Amount - Refund.Amount; } }
public double TotalPrice { get { return Sales.Price - Refund.Price; } }
}
public class StatisticAggregates
{
public int Amount { get; set; }
public double Cash { get; set; }
public double Cashless { get; set; }
public double Price { get { return Cash + Cashless; } }
}
And I have a projections list like this:
Aggregates alias = null;
new List<IProjection>
{
Projections.RowCount().WithAlias(() => alias.ChecksAmount),
Projections.Sum(() => sale.Total.Amount).WithAlias(() => alias.Sales.Amount),
Projections.Sum(() => sale.Payment.Cash).WithAlias(() => alias.Sales.Cash),
Projections.Sum(() => sale.Payment.Cashless).WithAlias(() => alias.Sales.Cashless),
Projections.Sum(() => sale.Total.RefundAmount).WithAlias(() => alias.Refund.Amount),
Projections.Sum(() => sale.Refund.Cash).WithAlias(() => alias.Sales.Cash),
Projections.Sum(() => sale.Refund.Cashless).WithAlias(() => alias.Sales.Cashless),
};
and transforms query with query.Select(projections.ToArray()).TransformUsing(Transformers.AliasToBean<Aggregates>();
In runtime TransformUsing() throws an Exception:
Could not find a setter for property 'Amount' in class 'Namespace.Domain.Services.Aggregates'
This is quite expected, because of NHibernate select the name of the property from a member expression (without leading member access).
So, how can I setup projections, which will fill in property of property Aggregates class?