okay so i figured it out. they *moved* that functionality to where you have to go to the Federation tab -> change the selection from "Limited" to "All" -> search for the domain in question and click it -> click the "Accounts" button
jesus CHRIST. why did they fucking CHANGE This.
@aescling no i was looking for all account that we have record of from domain
there used to be a field on the Accounts administration screen that you could just. *filter* by that.
its not there anymore