Friend has a new desktop and has a specific preference for having multiple windows of the same browser open. On Windows 10 I found that's accomplished via: Settings/Taskbar/Combine Buttons on ...

Learn to always open desktop folders and external folder links in new tab of File Explorer in Windows 11/10 using Folder Options and Regedit.

Bring the window in Safari to the front that contains tabs you want to move. Select Bookmarks > Add Tabs for These X Bookmarks.