How to create get/set delegates which can work with an object that doesn't own those get/set property?

Let's assume that I have those classes below;

public class FirstClass
{
    private SecondClass secondClass;

    public SecondClass Second { get => secondClass; private set => secondClass = value; }
}

public class SecondClass
{
    private int x;

    public int X { get => x; set => x = value; }
}

What I am trying achieve here is creating delegates;

Func<object, object> : Getter for X in the SecondClass, but it should work with an object of FirstClass

Action<object, object> : Setter for X in the SecondClass, but it should work with an object of FirstClass

With some efforts I was able to create this;

private static Func<object, object> BuildGetter(MethodInfo method)
{
    ParameterExpression obj = Expression.Parameter(typeof(object), "obj");

    Expression<Func<object, object>> expr =
        Expression.Lambda<Func<object, object>>(
            Expression.Convert(
                Expression.Call(Expression.Convert(obj, method.DeclaringType), method),
                typeof(object)),
            obj);

    return expr.Compile();
}

However this Func<object, object> only works with an object of SecondClass while I want to make it work with an object of FirstClass. So I am far from what I want to achieve here.

The project I am working on is much more complex, but I tried to simplify it. I am trying to get the MethodInfo for the get property of X, using reflection starting from the FirstClass.

So, How can I create getter/setter delegates which will work with the object of the FirstClass?