Hello Aldo,

GetPropertyValue is an extension method that Filter function does not support. Under the hood, an expression passed to the Filter function is translated into ElasticSearch query, so there are certain limitations on what can be used in Filter. 

if you need to speicfy a property name dynamically, you can use ExistsFilter:

var results = searchClient.Search<PageData>()
    .Filter(new ExistsFilter(TypeSuffix.GetSuffixedFieldName("Name", typeof(String))))
    .GetContentResult();

Note that you need to speicfy the property type as a second argument of the GetSuffixedFieldName function.