Need Tokens based on our Custom DFFs to add to the Notification

We are using a Pipeline Requisition Type and similarly the Candidate Selection process (CSP). In the Requisition Creation process we have added certain DFFs as per Client Requirement. Now, at different Phases of the CSP, we are triggering notifications for the Hiring Team and Candidates. In those Notifications (Created using Recruiting Content Library), we had a requirement to fetch few values from the Requisition with the help of Tokens. In the list of Tokens, we want to have the Tokens particularly for the DFFs from the Requisition.
Need your Advice to accomplish this.