Thread:Project:Support desk/Filter on categories

I need to filter some separate categories where the same page is present. I give an example to explain better.

The page "Command1" is present in the categories "System Commands", "SysABC" and "SysXYZ" The page "Command2" is present in the categories "System Commands" and "SysABC" The page "Command3" is present in the categories "System Commands" and "SysXYZ" The page "Command4" is present in the categories "User Commands" and "SysXYZ" The page "Command5" is present in the categories "User Commands" and "SysABC"

I wish to see:

"Commands" category with:
 * System Commands
 * User Commands

And then "System Command" category with the sub categories:
 * Command1
 * Command2
 * Command3

SysABC category with the sub categories:
 * System Commands
 * User Commands

And then "System Command" category with:
 * Command1
 * Command2

How I can organize the categories to have these filters?

Thanks in advance for the advice.

WT