to edit a post, Options (upper right) edit.
So tell me what you options are in the edit citation:more menu? Is page numbers an option? I have trouble remembering software options in a version I used in 2012.
What reference type is “Coldstream”?
Remind me again what output style you are using? Can you attach it (Attachments: choose file below your reply box).
Are these footnotes or in-text citations?
Finally, you could do {Gounaris, 2007 #53 pg. 89; Coldstream, 2003 #77 pg. 306; Vink, 1997 #82 pg. 126; Weiberg, 2016 #4493 pg. 67} or what ever punctuation/text you want to appear.
BTW - my take on why the second step, is - in your example you have 4 inserted citations in the group. You could edit each one when they are formated in one step – from the more window, you would click on each record citation and addthe prefix, suffix (or page numbers if that is an option in X5). If it is one citation, then it could be easier to do in one step, but when multiple, it is far more efficient to have the second step to select the one(s) you want to amend.