Not sure if what I am trying is possible or not, but I'd like to reuse a linq expression on an objects parent property.

With the given classes:

class Parent {
 int Id { get; set; }
 IList<Child> Children { get; set; }
 string Name { get; set; }
}
class Child{
 int Id { get; set; }
 Parent Dad { get; set; }
 string Name { get; set; }
}

If i then have a helper

Expression<Func<Parent,bool> ParentQuery() { 
  Expression<Func<Parent,bool> q = p => p.Name=="foo";
}

I then want to use this when querying data out for a child, along the lines of:

using(var context=new Entities.Context) {
 var data=context.Child.Where(c => c.Name=="bar" 
 && c.Dad.Where(ParentQuery));
}

I know I can do that on child collections:

using(var context=new Entities.Context) {
 var data=context.Parent.Where(p => p.Name=="foo" 
 && p.Childen.Where(childQuery));
}

but cant see any way to do this on a property that isnt a collection.
This is just a simplified example, actually the ParentQuery will be more complex and I want to avoid having this repeated in multiple places as rather than just having 2 layers I'll have closer to 5 or 6, but all of them will need to reference the parent query to ensure security.