The leaves in your photo look very similar to my Thyrsacanthus plants, but it's clearly not that.
I'm not familiar with Dorstenias, but I did a bit of online searching, and there are quite a few species, with not many online photos. Like their mulberry relatives, I think the leaves on some plants can be lobed and unlobed. I'm not sure if that disk thing in your photos is a flower or fruit, but it's not like anything I've seen before. It does look like it belongs to some sort of Dorstenia, though, I agree.
The photo in the plant database for
D. choconiana shows a plant with deeply lobed leaves, but there's a photo at Wikimedia Commons that shows a plant with unlobed leaves that look somewhat like the plant in your photos.
https://commons.wikimedia.org/...
That's my best guess, but I'm not exactly brimming with confidence that it's correct, lol. I wonder if you could e-mail your photos (or a link to this thread with the photos) to someone at the garden to see if someone can tell you the correct name?
Good luck!
Virginia