I just finished the HotS campaign on Brutal. however after, i did some save hopping to circle back and get some achievements I missed, lowering the difficulty where needed. The Brutal Achievement says I only have Brutal 15, not Brutal 20. Thing is, I have no idea which mission(s) I’m missing for Brutal. WoL would tell you which you had left, I dont see anything like that for HotS. I looked in the Master Archives, and none of them say I beat them on Brutal (but I have the achievements so I know I did). Is there any where that will tell me which missions I’m missing? I REALLY don’t want to go through it all again on Brutal lol.
Unfortunately, no. That was a WoL thing only. Neither HotS nor LotV has that list inside the achievement.
Each completed play through of the campaign resets the Master Archives to which ever difficulty(s) you used for that play through.