The Indicator Awareness UI component is used to communicate the amount of Awareness a group of agents has towards a specific game object (usually the Player).
The component shows the Awareness value taking as a point of reference a specific game object and gathering all agents around a specific radius.
If your game has Perception agents that you don't want to display their awareness, you can filter them at the bottom of the component. For example, you can filter them by their game object tag and only display those that are marked as enemies.
The demos included in the Perception module come with a prefab that is ready to be dragged and dropped onto your scene.
If you want to build your own UI it is highly recommended duplicating and modifying the one that comes packed with the module.