Within Teamwork, you can bulk edit active tasks from multiple projects across your site.
Go to the Everything area of your site and select the Tasks subsection.
In the Tasks area, select the option button (three dots) in the top right and choose Bulk Edit from the dropdown.
Note: If you have a filter applied when attempting to bulk edit tasks, it will only bulk edit those tasks found via the filter, not all tasks on the project(s).
Once you have selected the relevant tasks, you can use the Preview Selected Tasks link at the bottom of the modal to show them all in a list.
Click the Next button to choose which task properties to update, including tags, priority, start or due dates and progress.
Click the Update button to apply your changes to the selected tasks.
For more information, see: Viewing Active Tasks Across All Projects