what if i want to do the same thing but just to the combo box being displayed by the editor template. how can i access the datasource for the combo box?

{
columnKey: "MapToUserGroup",
required:false,
editorType:"combo",
editorOptions: {
mode:"dropdown",
id: 'mapToUserGroupComboID',
dataSource: mapToUserGroupList,
textKey:"Name",
valueKey:"UserGroupID"
}
},