C# How to access a variable in a script from an instance with the same script?

Hello.

I have set up some code which instantiates and gives tags to a couple of objects. This works fine.

When one of the objects are clicked on, its tag is stored idStart = gameObject.tag; when another object is clicked I store its tag in the same manner.

So to avoid confusion. Object 1 is pressed, object 2 is pressed. Object 2's script then changes the variable in object 1's script. How would I go about doing this.

This is the code in the script where everything is to be handled. At the bottom, the line dotScript idStart.dotValue--; is supposed to change the value of object 1's dot value

 if (!isClicked)
         {
             isClicked = true;
             //dotValue-=10;
             idStart = gameObject.tag;
             transform.localScale = new Vector3 (dotValue / 100, dotValue / 100, dotValue / 100) * 5;
             xStart = transform.position.x;
             yStart = transform.position.y;
             zStart = transform.position.z;
         }
         else
         {
             //dotValue+=10;
             idEnd = gameObject.tag;
             c = 10;
             transform.localScale = new Vector3 (dotValue / 100, dotValue / 100, dotValue / 100) * 5;
             isClicked = false;
             xEnd = transform.position.x;
             yEnd = transform.position.y;
             zEnd = transform.position.z;
             for (int i = 0; i<=c;i++)
             {
                 Instantiate(capsualPrefab,new Vector3(xStart+Random.Range(0.1f,1.9f),yStart+Random.Range(0.1f,1.9f),zStart+Random.Range(0.1f,1.9f)),Quaternion.identity);
                 dotScript idStart.dotValue--;
             }
         }

Any help is appreciated.

Thanks for your time and I will supply any further information if it is required.