My current git commit history looks like -
git log -4 --graph
*   commit B
|\  Merge: D C
| | 
| | 
| * commit C
| |
* | commit D
|/  
|
|
* commit E 
The merge commit B contains some additional changes apart from the (D + C) merge change.
I want to squash the latest merge commit B with the past 2 commits C and D.
I want my commit history to look like -
* commit A (B+C+D)
|
|
|
* commit E
