I can see some issues with what you have here. It starts with normalization. You really should only have 1 of those UserAccess values per row. I am guessing that only 1 column per row is not null? I would either split this into three tables or add a new column to identify which type of UserAccess it is.

If you split out the access into 3 tables your query might look something like this.

SELECT *

FROM Employees e

JOIN DepartmentAccess a ON e.DepartmentID = a.DepartmentID

join OfficeAccess oa on e.DepartmentID = oa.DepartmentID

join RegionAccess ra on e.DepartmentID = ra.DepartmentID

WHERE e.EmployeeID = @user-id

Another option might be to use a UNION ALL for the three types. Something like this.

SELECT *, 'Dept' as AccessType

FROM Employees e

JOIN UserAccess a ON e.DepartmentID = a.DepartmentID

WHERE a.UserID = @user-id

UNION ALL

SELECT *, 'Office'

FROM Employees e

JOIN UserAccess a ON e.OfficeID = a.OfficeID

WHERE a.UserID = @user-id

UNION ALL

SELECT *, 'Region'

FROM Employees e

JOIN UserAccess a ON e.RegionID = a.RegionID

WHERE a.UserID = @user-id

You will notice in all of those I moved the filtering to the where clause instead of on the join. It will work the same but I find it a lot easier to read.