The setting you would want to change is in the style.
In EndNote you can go to Edit > Output Styles > Open Style Manager > locate the style you are using > Click Edit > go to Author Lists under Bibliography > here change the setting under For Subsequent Works by the Same Author change the setting to “Print Author List as defined above”. > go To File > Save As > (EndNote will not allow you to change the existing style in EndNote but will always apply the change to a copy of the style) Click Save to save the changes to a copy of the style > close the style window.
You would then switch styles in Word using the steps on our website.
I am trying to do a similar thing. I am trying to format a citation as: Poulos and Mattes (1969a, 1969b). But I get: Poulos and Mattes (1969a), (1969b) by excluding the author in the second citation in the format menu.
How do I combine the year citations into the parentheses?