how to bind the data for radiobutton group in XML view?

Hi Team,

Am unable to bind the data for radiobuttons, am using XML view,

I have tried like below, but am getting errors.

<RadioButtonGroup id="rbg_id" items="{oDataRateAmnt>/SlabTypes}"  columns="2" selectedIndex="{oHeader>/rateAmntCode}"  >

     <core:Item id="IdItems" key="{oDataRateAmnt>SlabTypeCode}" text="{oDataRateAmnt>SlabTypeDesc}"></core:Item>

</RadioButtonGroup>

Binding model is:

var oModelData = new sap.ui.model.json.JSONModel(aData);

this.getView().byId("rbg_id").setModel(oModelData, "oDataRateAmnt");

this.getView().byId("rbg_id").bindAggregation("items","oDataRateAmnt>/", that.getView().byId("IdItems"));

error--> Uncaught Error: "Element sap.ui.core.Item#idschemecrt--IdItems" is not valid for aggregation "buttons" of Element sap.m.RadioButtonGroup#idschemecrt--rbg_id

same error if am including buttons tag,

<buttons>

   <core:Item id="IdItems" key="{oDataRateAmnt>SlabTypeCode}" text="{oDataRateAmnt>SlabTypeDesc}"></core:Item>

   </buttons>

I have followed this thread also

mutiple model bind to RadioButtonGroup

but am unable to bind for XML

please suggest me.

Thanks,

Preethi