The active mission has an icon and distance displayed for the player, so they can see the location of the objective, whilst the description is displayed in the top right of the HUD.
The Mission Log uses a Blueprint Widget with dynamic scroll lists to show all of the missions. This allows for new objectives to be set for missions quickly as an Actor just has to be selected within the Level for the Mission Tracker. Individual Actors then need a Mission Objective component attached.
As I have already implemented an Interactive Actor class, I extended the Interactive Actor behaviour so when the player interacts with that actor, if it is an objective, a flag is set which the Mission Tracker checks. If the flag is set the Mission Tracker knows that the objective has been completed.
Although this system has some drawbacks currently, such as not being able to have an area based objective, it does work very well when using Interactive Actors. Overall, this early version of the Mission Tracker and Log works well and is very easy and quick to use for creating new missions.