Replicate segmented cell style of macOS Big Sur

I am trying to replicate the style of the Finder. I have a NSSegmentedControl that is hosted in the menu bar, however, the style is a little bit different.

This is how the finder looks like:

And this is how my NSSegmentedControl looks like:

The width of the items seems to be a little bit bigger. There is also a small gap in between the items.

How can I replicate the Finder style?

It seems like there were two problems:

• Do not use a fixed width for your cells.
• Select the Rounded style.