I have the SharePoint lists 'Authorisation_Dates', 'People' & 'Departments'.



I have a form that uses the 'Authorisation_Dates' list as the data source. My problem is that I need one of the text fields on the form to display the department name.
To do this I need a formula that uses the employee ID from the 'Authorisation_Dates' list, matches it with the 'People' list, then uses the department ID from the 'People' list to match up with the department ID from the 'Departments' list and pull up the department name.
Any help on this would be appreciated.