Task ID to pass inside Escalation message event under User Input task

you can use getprocesstaskid function.

Thanks, i got it working using getprocesstaskid.

@guravav322: Appian has the OOB features to send a email notification with Task link in the same email unless it's being disabled at the global level in your environment.

If you want to retrieve the task id of the user input task ( T1 ) being assigned under a particular process model ( PM1), you can design a task report with context of Tasks by process model PM1 and use some data fields to filter a particular task based on some unique key values and once taskId value being received by calling a helper rule, use a!processTaskLink() to display the task link

I believe it is better to go with abhinav's solution i.e querying from task report because it will work even if process has multiple tasks as it let you to filter on basis of task names,other properties in report .

If you are having option to go back and forth i would recommend you to send email separately rather than as an escalation. This is because it will send multiple emails when ever they go back and forth. In most of the cases generally we send one email for task and we can control that if it is sent separately