Can't split Brep

Hi Guys,

I'm creating a simple star tesselation in hex cells and then using the elementary approach of attractor system varying the offsets (thickness) of the tesselation. I know exactly what I want to do, but I'm stuck in between. 

I've created the star pattern in the cells, and now want to split the brep of the hex cell with the polylines, so I could get the centroids of the split breps which I could use to define the offsets.

Everything is on a planar surface so splitting shouldn't be a problem, yet I'm getting an error. I flattened the data because they were different data structures, also tried projecting the curves on the brep so I could then use to split, but neither worked.

Can anyone please tell me where I'm going wrong? Or any other way of doing this?

Thanks for your help!