What type of relationship should I use for a lookup field that looks up to another record on the same object?

I need to include fields in a DDP from a record that is related to the DDP object via a lookup field.  The DDP object and the lookup object are the same.

So if the DDP object was record__c and the lookup field was partner__c that looks up to record__c as well, I'm trying to get the fields from partner__r.record__c.

Thanks.