Data Validation Against Two Ranges.

I'm trying to create a user request form. In one section of the form, the client will enter in a list of "Allowed Roles". These are roles that they have rec'd approval to use - these roles will span multiple applications. In a tab I've named Metadata, I've got defined ranges indicating the valid roles for particular applications. Want I'm trying to do is attempt to define a cell in the user form for one application that, using data validation, will present them with a drop down list of valid roles to choose. The stumbling block I'm encountering is that I need it to validate against "Allowed Roles" and the valid roles for that app.

For instance:

Allowed Roles range name could contain:
B1 B2 C1 C2 P2 P3 D1 D3 D5 M1 O1

Payroll Roles:
C1 C2 C3 C4 C5 M1 O1

The Payroll Roles (on the metadata tab) are static, not user alterable in any way, and in fact Metadata will be hidden. Allowed Roles will be entered into the form by the client themselves.

Can I use data validation to create a drop down to only allow the user to pick a value that appears in both ranges? So they couldn't select C1 (since it's an Allowed Role, and a Payroll Role), but not C3 (not an allowed roled), or D3 (not a Payroll role).