How can I create a tree using two different tables

How can I create a tree from two different tables using PHP Connector (Dynamic load)?

I have a domain table and the group table.

How can i create parent nodes from Group table And create child nodes from Domain table?

I obtain your advice .
Thank you.

Group Table ( parent node)
groupId, name
G1 SiteA
G2 SiteB
G3 SiteC

Domain Table ( child node)
id, url, groupId
1 dhtmlx.com G1
2 google.com G1
3 yahoo.com G2

You may consider TreeMultitableConnector or use own solution instead of Connector.