Without wanting to dampen spirits, I've seen that stave in person, and although it may be just 5" deep and wide (I measured 4" deep on it once you remove the bottom of the triangular belly cut), it was cut on such a chamfer that you can only get one full thickness longbow down the middle. It's English yew as well, so not as dense as Italian/American and needs a slightly wider profile for a warbow (I assume by the OPs other posts that's his interest, plus it was advertised as a warbow stave)
I think going for more than one would be a tad greedy, and run the risk of ruining a potential bow. All personal opinion of course, but I couldn't find two bows in there when I saw it. I'm no expert though, and may have been erring on the side of caution.
If you wanna make a warbow, I'd go for one. If you're looking for light weight longbows you may just be able to squeeze two side by side, but make certain there's enough thickness in both handle areas without the sides angling in too much on the stave.
This is what the rest of the guy's staves look like, with two bows laid out in cross section
The chamfer is pretty steep so you run into the risk of losing two, rather than gaining one.