Switch between tabs from different tab groups in vscode

First, you can use Ctrl +<group number> to shift the focus to the group you wanted. Then you can use Ctrl + Tab to shift between the tabs within that group.

Let's say I have 2 groups open and I wanted to shift the focus to group 2. I use Ctrl + 2. Later, I can focus on different tabs within group 2 using Ctrl + Tab.

(Ref) Other related shortcuts are here: https://code.visualstudio.com/docs/getstarted/keybindings#_editorwindow-management

There's an open feature request that complains about the unexpected behavior of workbench.action.openNextRecentlyUsedEditor:

workbench.action.openNextRecentlyUsedEditor does not behave as expected (#37366)

Note that it's not that the command doesn't do anything, but that it only does something if there's still another editor left in the recently used list (so it doesn't work as a toggle like Ctrl+Tab does).