There are several ways of accomplishing this.
This is one way that worked for me in Affinity Photo 2.
This is for 14 segments (almost any number of segments can be used).
I chose 14 segments because I needed seven segments in a half circle. More on this later.
Select the Cog Tool
Draw a (Cog) circle
(hold Shift to draw a perfect circle with matching height and width if required)
Settings
Teeth: 14
Inner radius: 70%
Hole radius: 70%
Tooth size: 100%
Notch size: 0%
Curvature: 0%
Click Convert to Curves in the top toolbar
Layer > Geometry > Divide
After dividing the cog, the circle (cog) is gone and I now have 14 new layers, each representing one segment of the circular bar chart I need.
I only needed seven of the segments to be seen in a half circle, so I hid the other seven layers.
In my case I wanted each segment to have a unique color. So, I clicked on each layer one by one and changed the color.
Because I wanted separation between each segment I chose to add a white Stroke to each segment which would match the white background I was using to visuall add separation. I chose 30 pts because this is a large (8,000 x8,000 px) circle and that amount of separation looked good for this use. Tune your stroke pt weight for your needs.