I would like to figure out how can I create BPMN process's relationships within my process repository

The idea is to have a Parent process with for example Task A, Task B and Task C. Then I made a sub process or a child process with Task A, Task B and Task Y, so both taks A and B are shared with the Parent Process. When I modify Task A and Task B, these tasks are automatically modified as well in the sub-process.

I am using Confluence as the records management tool and draw.io as the process modeller tool.

A priori, draw.io does not support this scenario,

Can anyone suggest a different way or a different process modeller software which allow to do that?