Octagonal sphere

I am attempting to recreate this drawer pull and cannot for the life of me recreate this top sphere. I’m sure it is simple but I can’t seem to get it. It is a sphere but the top has like concave sides to it. I’ve added a ar screenshot of what I have vs what I’m aiming for.

Start with the diameter sphere you’d like to make.
This method applies to the other shapes of the drawer pull as well.

Great solution Mike.

Thank you so much. This has been driving me nuts!