How to copy tasks with dependencies from one project to another?

In the window that pops up, click on Copy to another project: 

After that, click on Continue

In order to copy tasks with their subtasks, comments, and files - just mark the corresponding checkboxes. And in order to save deadlines and dependencies while copying, simply mark the checkbox next to the Deadlines and dependencies 1. If needed, indicate the new date of the task's start2 or the previous date can remain unchanged. The starting point is the start of the earliest task copied.

Please, note: Tasks can be copied by any user who can set tasks, while only an administrator or the author can transfer tasks.

Attention: when there's a lack of nesting levels, subtasks are transferred to the level with a prefix of its parent task.