It’s easy.
You only needs a Widget and attach it to an Actor. To do this, go to User Interface, Widget and create it. Then, create an Actor and append the Widget to it. You can Attach this actor to Motion Controller, to Location … With Widget Interaction module in this actor, you can interact with this widget.
This is the info from unreal to achieve this.
Widget Interaction
https://docs.unrealengine.com/latest/INT/Engine/UMG/HowTo/InWorldWidgetInteraction/
Widget Creation
https://docs.unrealengine.com/latest/INT/Engine/UMG/HowTo/Create3DWidgets/
Regards!