Performance Tile - create a measure of maxium distance from CEO

Summary

How to create a measure of max of level

Content

Hi, 

we need to create a measure that is the maximum distance from CEO.

Level is calculated by the following formula:

 CASE WHEN "Parent Managers"."Parent Manager 15 Name" is NOT NULL THEN 15  WHEN "Parent Managers"."Parent Manager 14 Name" is NOT NULL THEN 14  WHEN "Parent Managers"."Parent Manager 13 Name" is NOT NULL THEN 13 WHEN "Parent Managers"."Parent Manager 12 Name" is NOT NULL THEN 12 WHEN "Parent Managers"."Parent Manager 11 Name" is NOT NULL THEN 11 WHEN "Parent Managers"."Parent Manager 10 Name" is NOT NULL THEN 10 WHEN "Parent Managers"."Parent Manager 09 Name" is NOT NULL THEN 9  WHEN "Parent Managers"."Parent Manager 08 Name" is NOT NULL THEN 8  WHEN "Parent Managers"."Parent Manager 07 Name" is NOT NULL THEN 7