ODA can only one level of file mirroring in disk groups

To have different type of file mirroring in the same disk group. The easiest way is to 

1. Define Normal redundancy disk group.
2. Define different templates for this disk group with Redundancy attributes set to "MIRROR", "HIGH" or UNPROTECTED.
3. Create tables space with these templates with incomplete_file_name.
    e.g.
    create tablespace test_data DATAFILE +data(template);

In ODA, all diskgroup are in High redundancy configuration. In this case, template attribute MIRROR and HIGH will both give three way mirroring. 

Reference to : "Oracle Automatic Storage Management Administrator's Guide"  11gR2 Page 7-16