minimal.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;

class Foo
{
    [SomeAttrib]
    public EntityLocalizer A { get; set; }
    [SomeAttrib]
    private EntityLocalizer B { get; set; }
    [SomeAttrib]
    public EntityLocalizer C;
    [SomeAttrib]
    private EntityLocalizer D;
}
public class SomeAttribAttribute : Attribute { }
public class EntityLocalizer { }
static class P
{
    static void Main()
    {
        Thing(typeof(Foo));
    }
    static void Thing(Type entityType)
    {
        var locFields = EntityLocalizationReflection.GetLocalizationFields(entityType);
        if (locFields?.Count > 0)
        {
            var entityObject = Expression.Parameter(typeof(object), "objParam");
            var entityInstance = Expression.Convert(entityObject, entityType);
            foreach (var loc in locFields)
            {
                var target = loc.Item2.MemberType == MemberTypes.Property
                    ? Expression.Property(entityInstance, (PropertyInfo)loc.Item2)
                    : Expression.Field(entityInstance, (FieldInfo)loc.Item2);

                var getter = Expression.Lambda<Func<object, EntityLocalizer>>(target, entityObject);
                getter.Compile();
                Console.WriteLine("compiled for " + loc.Item1);
                
            }
        }
    }
}

internal class EntityLocalizationReflection
{
    internal static List<(string, MemberInfo)> GetLocalizationFields(Type entityType)
    {
        MemberInfo[] fields = entityType.GetFields(BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic);
        MemberInfo[] props = entityType.GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic);
        return fields.Concat(props).Where(x => Attribute.IsDefined(x, typeof(SomeAttribAttribute)))
            .OrderBy(x => x.Name).Select(x => (x.Name, x)).ToList();
    }
}