Is there a way to link sub-task to the initial task?

matthew.ruth

Is there a way to link sub-task to the initial task? See below as an example:

Ideally, I would like the “New Material” to be project 3.1, etc.

JamesB

@matthew.ruth This would not be a column formula, but you could use this is the child Project ID cell.

=Parent([Project ID]@row)+".1"

jessica.smith

@matthew.ruth

If you don't mind adding a few hidden columns, something like this could work.

User would enter a Project ID on the Top Task level only.

Add a Auto Number System column "Auto" and a "Row" column. Both should be locked and hidden. The Row column will reference the Auto column to return the row number: =MATCH(Auto@row, Auto:Auto,0)

Create a "Project" helper column (can be locked & hidden) that will use a column formula to return the Project ID of the parent for all descendant tasks : =IF(COUNT(ANCESTORS()) = 0, [Project ID]@row, PARENT())

Add a "Task ID" column that will basically count all sibling tasks that occur above the child task in the row and then concatenates that value with the Project ID:

=IF(COUNT(ANCESTORS()) = 0, [Project ID]@row, PARENT([Project ID]@row) + "." + (COUNTIFS(Project:Project, =Project@row, Row:Row, <=Row@row) - 1))

Note, with this setup, the Task ID would update based on where the task is in the list. If it has to remain a non-changing, unique identifier this might not work as is.