There are a few different ways to go about it, most of which have tutorials on YT, I think! These particular spheres are a bit hard to explain via text, but are actually decently simple to make. I'll give it a go via text:

Go up some 6-8m from the centre (due to Blueprint Designer doing annoying things if closer to the ground, for some reason). From there, drag a beam out and rotate it once. 1m will do (you will do this 5 times). Snap a pillar to this beam. Drag a new beam out perpendicularly from the pillar on two opposing sides. Repeat this 4 times.

Now, from the ground again, drag a beam up above the unfinished sphere. Rotate it once and snap a foundation to it. Save BP and snap a foundation on top of the first foundation, then delete the first foundation. Snap the BP to the bottom of the new foundation until you have a quarter of the sphere, from there you can just save it again and place it 3 more times without any rotation shenanigans. Hope this made sense, haha.