If you have a collection of videos in a scene, like a video gallery, rather then each video having it's own video asset you could create a dedicated video layer.  This will allow for easier maintenance and lower resource consumption.  It will also provide a cleaner visual then having a collection of videos playing independently.

Here are the steps on how to do that:

1. Add layer to scene, we will name this the Video Layer.
    
2. Add a rectangle asset to the Video Layer, make the rectangle the size of the scene, change the opacity to 0.25.  The purpose of this rectangle asset is to stop interaction with the assets behind the video and shades the assets behind to show they can't be interacted with.  
   
   
3. Add a video asset to the Video Layer, make this the size you want your videos to be presented at.
    
4. Add a button to the video layer, add a trigger to the button to hide the Video Layer.  This will function as the "close" button to hide the layer when no longer in use.
   
   
    
5. Hide the Video Layer, as this will not need to be visible when entering the scene.
    
6. On your thumbnail/video add a trigger with the action to change video of the video asset on the Video Layer.  Choose the video you want it to change to.  You can also bind this value to a data feed that you would get from an Excel sheet or Headless CMS base.
   
   
    
7. Add another action to that trigger to show the Video Layer.
   
   
    

With it set this way when the thumbnail/video is clicked it will change the video and show the Video Layer.  Then the user can use the close button to hide the Video Layer.