I want heading to this:

Chapter 1
1.1
1.1.1
1.1.2
1.2

Chapter 2
2.1
2.2
2.2.1
2.2.2

Chapter 3.

and so on.

But i keep getting

Chapter 1
1.1
1.2

Chapter 2
1.3
1.4

Could someone provide me with a word file that does the numbering or can someone tell me how to do it?

Thanks a lot.