Start the transaction using transaction code KAH2
Double-click

Change cost element group : Initial Screen |

Enter the cost element group to be updated
and ![]()
Then you can:

Click on the group above where you want to add a new subgroup
and then click ![]()

Enter the code of the new group and its description
Be careful, when the code is created, you can not change it anymore. If it is wrong and not consistent with the existing codification, you must delete the group and create a new one. |

Click on the group you want to delete
and then click ![]()
The group to be deleted is highlighted in red

Click the button remove ![]()
Before deleting a group, make sure there is no more cost element included in the group otherwise you must move them before in another group. |

Click on the group you want to move and then click ![]()
The group to be moved is highlighted in red

Click on the group in which you want to include the group and then click
![]()

The group has moved

You can easily change the description of a group
Remember that hierarchies are used in reporting tools. To make them easier to read:
|

Click the group in which you want to include a new cost element
and then click
you can click several times if you want to include more than 5 cost elements

Enter the code of the cost element you want to include

Click on the cost element you want to move
and then click ![]()
The cost element to be moved is highlighted in red

Click on the group in which you want to include the cost element and then click ![]()
The cost element has moved

Once your changes are done
and 
There is a message at the bottom of the page 
You can leave the transaction