New UI Map Selection

Hello

I am trying to make a map selection, I've never done it before so I don't have a 100% understanding of how to do it. What I tried is this code which works but I am not sure how efficient is to instantiate a ui.

A second problem is that I have a button attached to the panel which once is made into a prefab the OnClick function in the inspector can't detect any GameObjects and if I select the scripts that has the function in it the only function that will be displayed is "MonoScript->String Name"

Also I am using Bolt instead of the default networking system.

 void Awake()
 {
     foreach (string maps in BoltScenes.AllScenes)
     {
         if (Application.loadedLevelName != maps)
         {
             (Instantiate(mapsPrefab, new Vector2(0, 0), Quaternion.identity) as Transform).transform.SetParent(this.gameObject.transform,false);
         }
     }
 }