How to change datasource of a group in portal

Hello Evryone,

I am using EP7.0

When I am creating a new group under User Administration->Identity Management ->Create new Group,

a new group gets created, but the data source of this group is "UME Datasource".

I want to change the data source of this group. The available data sources when I search the groups are "R3_ROLE_DS", "UME Datasource", "Built-in Groups Adapter".

But there is no way that I can create a group with , say R3_ROLE_DS data source. On creation of a new group it just asks for a group name and group description. It always creates a group with a default data source "UME Datasource".

Can anyone help me on this.

Thanks

Vikram