Hello Rob,

Thank you for posting in our forum.

In order to pass the desired roles for your data what I can suggest is to use the discoverProperties option of the OlapXmlaDataSource. This allows you to sent additional properties with every discover request. The object is treated as a key/value store where each property name is used as the key and the property value is the value. In your scenario I believe the Roles property is what you are looking for. This property lets the user connect using a role other than the one he is currently using. For example:

 $(function () {
            var dataSource = new $.ig.OlapXmlaDataSource({
                serverUrl: 'http://sampledata.infragistics.com/olap/msmdpump.dll',
                catalog: 'Adventure Works DW Standard Edition',
                cube: 'Adventure Works',
                measureGroup: "Internet Sales",
                rows: "[Sales Territory].[Sales Territory]",
                columns: "[Product].[Product Categories]",
                measures: "[Measures].[Internet Order Count]",
                discoverProperties: {
                                    Roles: "Your role here"
                                }
               
            });

Some further reference about supported XMLA properties could be fount at:

http://technet.microsoft.com/en-us/library/ms186627.aspx

I hope you find this information helpful.

Please let me know if you have any additional questions regarding this matter.