On your PPS profiler or appliance using a remote profiler go to the realm on which you'd like to create a role mapping rule using a custom expression.
1. Got to Users > Realms then select the realm you desire.
2. Select Role Mapping and New Rule
3. At the top of the page select the drop down for "Rule based on" and select custom expressions, then click update. When the page reloads select Expressions.

4. As of 9.1R2 the Expressions Dictionary does not contain preloaded expressions for profiler so they need to be created manually.
5. Choose the attributes you want to use in the role mapping rule.
Example: I have a profiler group for HP Printers, I also use device sponsoring so I would like a role mapping rule specifically for approved HP Printers.
This is the completed custom expression.
deviceAttr.groups = "HP Printers" and deviceAttr.status = "approved"
Profiler device attributes start with "deviceAttr." and end with the value. The value should be started and ended with single or double quote.
6. Once you name and save your custom expression it will be added to the Expressions Dictionary under "Your Expressions".
7. After saving your custom expression and closing the Expressions Dictionary you will be able to select your new custom expression from the role mapping page.
8. As we continue to develop our Profiler we'll be adding new values, to see the current list of available values create a new role mapping rule. This time under "rule based on", at the top of the page select device attribute, and select update. When the page updates you'll see a drop down menu called "Select an attribute" this will contain a list of all of the currently available device attributes.