I would suggest just making a similar sketch to your original sketch on the top surface and making an extruded cut. Then use a circular pattern as needed.
Thanks, Steven, I will try that.
..it is not clear to me why you want to wrap around the sides?...
.., as you have it.. you can cut that pattern using a copy surface and surface thicken cut...
although, if you don't need that cut but just the splits on the sides,.. you could thicken that surface (not cut/merge) and then , remove the outside face to make it a surface, then, intersect the faces and with the sides... that would give you the split or wrap in the side faces.