Recruiting Fast Formula

We are capturing previous assessments taken by a candidate configured in a person extensible flexfield in the candidate extra information section.

We want to write some fast formulas of type "Recruiting candidate selection process", where we want to fetch the previous assessment details of a candidate (the Person EFFs) that he/she has taken before.

We want to attach this fast formula in a selection process created using 'Configure candidate selection process'.

We will be attaching this configuration to a job requisition where multiple candidates will apply.

May we know how to get the Person EFFs inside the fast formula and whether it is possible in the fast formulae or not? Our use case is to check if the candidate has taken the same assessment(values stored in Person EFFs as explained above) and then move him/her to the next state accordingly.