Click on window icon to open window list popup.
Step 1: Select position.
Select position in other window where
you want to set current tab group
Step 2: Select window
Click on wondow's title to set current tab group
inside selected window at selected position.
Last step: Create new window
Click on new window to open create dialog. Set window title and click on create button. New window will create and tab group will move into this window.