Create Unique List when column locations change

I have a spreadsheet that has alot of information within it regarding company and employee demographics. INDEX MATCH has been effective, however the columns within the spreadsheet have been changing locations and thus, making INDEX MATCH with specified ranges ineffective.

I am looking for a formula that will create a unique list of employee ID's based on a match of "employee" in a column labeled Relationship. The challenging part is the employee ID column and the relationship column can be anywhere on the spreadsheet from column A:DA. The formula will search the range A1:DA1 to identify the column "Relationship", and use that columns range to match "employee" to create a list of employee ID's.

If possible, 365 formulas will not work in this instance.

Here is a copy of the workbook: