On the career site map, zooming in causes the numbers to break into split into the specific regions

Summary: On the career site map, We observed that the job requisition postings are initially grouped together, and as you zoom in or click on the numbers, they break down into specific regions or locations. Could someone clarify the logic behind how these postings are grouped when zoomed out and how they are divided when zoomed in? I'd greatly appreciate your explanation. Thank you!

See the screenshot below for your reference.

This is an example of zooming out

This is an example of zooming in.

Thank you,

Misba