Make a custom inspector that shows a group of variables in form of list

I want to make my inspector look clean and tidy, so I’m asking this question.
I have 3 variables, (Z offset, Y offset and X offset) and I want to “hide” them under some kind of arrow. Think of how Unity handles lists and arrays, you click on the arrow and it shows the values to edit.
In this case, I want to make something like that to show these 3 variables.
Is this possible?

public class MainClass: MonoBehaviour
public SomeClass someClass;

     void Start()
          //Example usage;
          if(someClass.xOffset == 0)
               someClass.xOffset = 10;

class SomeClass 
     public float xOffset = 0;
     public float yOffset = 0;
     public float zOffset = 0;

I managed to do this by using EditorGUILayout. (I don’t think I need to state my code, since the docs say everything).

Thanks everyone that tried to help me.