I am trying to make a formula field that options the link in a sub tab in the lightning console application. The formula field that I am using is: HYPERLINK("lightning/r/Financial_Account__c/" & Id & "/view", Name&"/"&Record_Type_Name__c, "_parent")

Currently this formula field is opening in a new tab rather than displaying as a subtab. 

Please comment if you have any ideas on why the "_parent" is not functioning the way it should.