SWE Origin-Dest. Arrows

Hi everybody. Can you please say me .. How can i adjust this "d" distance automatically. for example i want it shorter. but i couldn't manage it. İ get into Conf. -> Project -> Origin-Dest -> f(x) to configure this feature by changing the formula. but it does not work. Please help me at this point. How can i change this distance automatically.??

SolidworksElectrical