In the Tasks panel, we have the “Move Tasks” functionality which will allow us to carry out three main actions:
To access it, click on the file icon at the top of the tasks panel, next to the name of the project (or the name of the task, if it's a subtask) 
This icon only appears when you move the cursor next to the task name.
Move a task to a project
In the Tasks panel, select the “Move Task” option.
In the “Search” tab, you will find a list of recent projects; you can select one by clicking on its name.
To search for a specific project to which you want to move your task, type the name or ID of the project into the search engine.
Once you have selected the project to which the task will be transferred, click on the “Move” button. Finally, it will show us the “task journey” and ask for confirmation with the blue button in the bottom right-hand corner.
Convert a task into a subtask
To convert a task into a subtask, we first have to go to the task we want to convert into a subtask of another existing parent task.
Go to the task panel and click on “move task” in the top left bar.
In the Search tab, we'll find the list of recent tasks; if we find the list of projects, we'll click on the slider.
Finally, you can select a task by clicking on its name, or you can enter the task's name or ID into the search engine.
When we click on “Confirm” our task, it will become a subtask of the task we selected.
Converting a subtask into a task
To convert a subtask into a task, go to the subtask you want to turn into a task and click on “Move Task”.
This will open the modal that will be the default in the list of subtasks.
Then select the gray “back” arrow on the left, which will take you to the list of tasks, and click “move”.
This will open a box showing the “journey” of our task and asking us to confirm the change.
When you click “confirm”, the subtask will be transformed into a task.