Data Connector is formerly known as Genesis. Adobe Data Connectors provide a complete development ecosystem to help Data Connectors partners integrate their products and services into the Adobe Experience Cloud.

Segment created in Adobe Analytics can be reused in Data Connector as Remarketing Segment.
Sometimes the segment is not available in Data Connector. There can be multiple reasons for it like

1. Data Connector owner does not have access to segment
2.The segment is not shared to owner

The major point often get missed, is the compatibility.If the segment is not compatible to Data Warehouse then it will not be available under Data Connector for re-marketing segment.