In legion there are 4 breadcrumb quests to the next zone: Pressing the Assault, Isle Hopping, Scouring What Remains and Master of the Isles
First of all you need to get each quest to pop.
After the first zone (dungeon quest) you will get Pressing the Assault,
after the second zone (dungeon quest) you will get Isle Hopping,
after the third zone (dungeon quest) you will get Scouring What Remains ,
and finally after your fourth zone (dungeon quest) you will get your last breadcrumb quest Master of the Isles.
If u have trouble getting credit for those quests cause u have been to others zone already or you are trying go get them on your main in party-sync, there is a little workaround for it. Therefore you need to join a group with a character that has the quest Stormheim available. Then you simply party-sync with the 2nd character, accept Stormheim and it will autocomplete your breadcrumb quest.
Yes, it also works for Master of the Isles even though there were only 4 zones back in the days.