To connect to multiple VPCs across different Regions using Direct Connect, the best option is to use a Direct Connect gateway and transit gateways. A Direct Connect gateway allows you to associate multiple virtual private gateways and transit gateways with the same Direct Connect connection. A transit gateway acts as a network hub that connects multiple VPCs and on-premises networks. By creating inter-Region peering connections between the transit gateways, you can enable cross-Region communication. Therefore, the steps are:

•Create four virtual private gateways and attach them to the four VPCs that need access from the on-premises location.

•Create a Direct Connect gateway and associate it with the four virtual private gateways.

•Create four transit VIFs on each Direct Connect connection and associate them with the Direct Connect gateway. A transit VIF allows you to connect to a Direct Connect gateway using a private ASN.

•Create an association between the Direct Connect gateway and the transit gateways in each Region. This will enable the on-premises location to access the VPCs that are attached to the transit gateways.