Filter BPM Task based on custom attribute using BPM ODATA

Hi All,

I have a requirement to filter BPM Task based on custom attribute. I used below ODATA and it returns Bad request.

https://<server:port>/bpmodata/tasks.svc/TaskCollection?$filter=CustomAttributeData/<field_name> eq <value>.

https://<server:port>/bpmodata/tasks.svc/TaskCollection?$filter=CustomAttributeData/Name eq '<Field_name>'

Please let me know if i am passing a wrong parameter?

Thanks

Rathish