Here I made a quick example.
Brick wall section set up per @jimhami42. Use Copy/Rotate about the center of the arc for the wall. I left the short wall segment as a component and copied it with the bricks but you wouldn’t have to do that. The brick units are components containing the brick elements instead of leaving the bricks as individual components. The key is that all of your objects are identified as solids.
I created an angled cutter. In this case I used the Pie tool and rotated it at its apex. You could create the cutter any way you want. It also needs to be considered a solid component or group by SketchUp in order for the next step to work.
Using the cutter with Trim from the Solid Tools, I cut the tops off of the wall objects. Note that I now have 12 solid groups. The Solid Tools convert the components they modify into groups.
And exported as a .stl and imported into the slicer.
A lot of this could be simplified in SketchUp Pro with the addition of some extensions but this will work in SketchUp Go.