If you're using SXA it would depend on what you use to achieve this.
If you're using a Page List, you could set:
* for section one: the "Page size" in the control properties to 3.
* for section two: the "Offset" to 3
This way you have the same list only 1 will show the top 3, the other will show all others starting for the configured offset.
Danny Paul van Iersel