Here’s what you do:
1. In your search help, be sure to mark both EMPID and LOCATION as export parameters
2. Create a structure in the ABAP Dictionary which contains both your export parameters. For example, create the structure ZEMPLOC with fields EMPID and LOCATION
3. Attach your search help to BOTH fields of your structure (in ABAP Dictionary while defining the structure).
4. In your program, specify the structure you create with the statement: TABLES ZEMPLOC.
5. Use the fields of ZEMPLOC to define your screen fields. This should make your search help populate both fields when you use F4 for either of them.