A class has two member types in B4A: functions and properties. If the function returns an instance of a class, or the property holds an instance of a class with other functions and properties, then you can have things like MyInstance.MyFunction.MyFunction.MyProperty... etc.
For example:
MyEditText.Text.GetBytes("UTF-8").Length
MyEditText is an instance of the EditText class. It's an object. It has a Text property (String class). The String class has a function GetBytes. This function returns a byte array which has a single property: length.