I did some searching around, along with some experimenting. I have successfully put a tabber inside a tabber. Of course, this is nothing new; as we can see in this thread where I figured out the correct way to do it (of course, after trying a few ways of how not to do it). Click on each tab, and see how far I went in each tab. Feel free to examine the source code to see how I did it.
This is the first tab; a normal tab with no tabbers inside.
This is the second tab; a different tab with one tabber inside.
This is the third tab; a rather unusual tabber with a tabber inside of tabber that is inside of this tabber.
This is the first tab.
This is the second tab.
This is the third tab.
This is the fourth tab.
This is the fifth tab.
This is the fourth tab; now I considered making this tab have a tabber where every tab had a tabber where every tab had a tabber but that would be too complicated.
This is the first tab.
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This is the fourth tab.
This is the first tab.
This is the first tab.
This is the first tab.
This is the first tab.
I just went insane! ~~~~
This is the second tab.
This is the third tab.
This is the fourth tab.
This is the fifth tab.
This is the sixth tab. ~~~~
This is the second tab.
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This is the sixth tab.
This is the second tab.
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This is the fifth tab.