Greg, you must also use SQL condition. There is no "In" function in TExpression for now.
Eli, you can use this:
Results := Manager.Find<TUser>.Select(TProjections.ProjectionLilst
.Add(TProjections.Prop('UserId')
.Add(TProjections.Prop('UserName')
.ListValues;
then you can grab the values this way:
UserName := Results[0].Values['UserName'];