The checkbox:

Grouping Settings > Explorer enhancement settings > New Explorer tabs should open in the same folder

Does not appear to function.

If I enable this setting, close the Groupy settings window, re-open it and navigate to the setting again it will appear disabled.

It also appears that the underlying state of this setting is enabled by default despite what the checkbox shows; If I create a new explorer tab (eg. Ctrl+T) the new tab will always be in the same folder as the previously selected tab.

I personally prefer this behavior, but wanted to mention that this settings UI appears to not function as you would expect.