In the LLBLGen Designer, go to the "Edit Properties" of the Conditions Entity.
In the "Fields on relations" tab, you will find both of the fields mapped to these relations.
These are the entity objects representing related Data Entity, attached using each of the FKs.
It is recommended that you rename these fields to recognize them easily in the code.
So instead of Data and Data_ (as they might be created by default), you can rename them to LeftData and RightData.
Save the project and re-generate the code.
Now you should have 2 recognizable prefetchPath properties, something like: PrefetchPathLeftData & PrefetchPathRightData.
So now you can use both of these prefetchPaths to prefetch both of the entities when you fetch the Condition Entity.