Use Twig variable as a property name of an other Twig variable

I must use a Twig variable as a property for another Twig variable.

In a for loop, I get the properties of a specific entity and want to use those properties to get the property-content for an entity variable in an other for loop.

Some code to make this clear:

{% for entity in entities  %}

{{entity.foo}}, {{entity.bar}}<br />

{% for property in specialdynamicproperties %}
{{entity.property}} <!-- property has the content foobar for example, I want to use it as the property accessor for entity -->
{% endfor %}

{% endfor %}

Thanks.