average value ignoring filters

I need to get the average resolution time (for service desk tickets) for global staff.  I already got a working measure to calculate this average based on the employee name slicer.  I need a 2nd measuer that gets the same value but for all staff, ignoring that slicer but keeping the filter from the "opened_at" slicer (which factors in when the tickets were opened).

I'm not sure where to include "ALLEXCEPT" in this formula below.

I hope that makes sense and I didnt confuse you 🙂

Avg Global Resolution Time = 
( CALCULATE(
    AVERAGE(incident[Resolution Time in Days]),
    FILTER(
       incident,incident[assigned_to] IN VALUES('SD Engineers'[Engineer])))
) + 0