Queries
A relationship between a JDO and the data object of an entity does exist. The DynamicAttribute data object queries are supported without any limitations via the findByMultipleParameters query method. Dynamic attributes can be used with this method, for example, in the Search Bar configurable user interface.
If a dynamic attribute is used in a query, the condition needs to be translated in two parts:

customAttribute.attributeMetadata.attributeName == paramName && customAttribute.attributeValue == value