How to individually add the outline effect to copies of a trace-triggered BP actor

I am working on a project featuring a character to “activate” some cubes in the scene by looking at them, and then to perform transformations such as move, rotate, scale, and delete. I am now able to individually enable and disable inputs on different copies of a BP actor. I can also individually transform the BP actor copies. But I cannot figure out how to add outline effect individually. The current BP scripts always enable outline effect on multiple objects. I know what the problem is but cannot find a solution. Any help?