WowAce

The following seems to fix it for me:

diff -ur a/AngryWorldQuests/QuestFrame.lua b/AngryWorldQuests/QuestFrame.lua
--- a/AngryWorldQuests/QuestFrame.lua	2018-09-23 04:36:30.000000000 +0200
+++ b/AngryWorldQuests/QuestFrame.lua	2018-09-23 15:30:37.000000000 +0200
@@ -798,7 +798,8 @@
 		end

 		if selectedFilters.EMISSARY then
-			local bounties = GetQuestBountyInfoForMapID(UnitLevel("player") and MAPID_KUL_TIRAS or MAPID_BROKENISLES)
+			local mapID = QuestMapFrame:GetParent():GetMapID()
+			local bounties = GetQuestBountyInfoForMapID(mapID)
 			local bountyFilter = Config.filterEmissary
 			if GetQuestLogIndexByID(bountyFilter) == 0 or IsQuestComplete(bountyFilter) then bountyFilter = 0 end
 			for _, bounty in ipairs(bounties) do

Mind you, I haven't tested this yet on the Zandalar and Kul'Tiras maps (I've completed all emissary quests, need to wait a few hours for proper testing), I'll post a follow-up comment once I've done that.

Since your add-on shows all the BfA WQs when one is viewing the Azeroth map, I'll also look into special-casing that map so the emissary filter works on the list as expected (even though that map has no blips).

Revised version that 1) re-uses displayMapID instead of getting it again, and 2) special cases Azeroth. Will follow-up after I've had a chance to test it for BfA in an hour.

Edit: removed obsolete diff

Tested against BfA zones, now using the proper default map for emissaries based on player level. Since BfA world quests aren't available till the player reaches level 120 I changed the test from "> 110" to ">= 120", which lets my level 111-119 toons still easily see the Legion WQs.

Edit: removed inline diff in favor of attachment.