Add values while keeping Selected Slicer Value

Sample File with data is as below:

PBIX File

I have 2 tables:

1. Calendar table that has dates between 2022 - 2025

2. Events Table that has Event, Role, Department, Start date, End Date

Start Date has a relationship to the date in the Calendar table i.e. each date in the Calendar may have one or more events that start on a date.

I have 5 slicers: Role, Department on the Events and Year, Month, and Quarter on the Calendar table. Only one year can be chosen. But multiple positions and departments can be chosen.

I have a particular department, whose data needs to be shown irrespective of what role and department are chosen on the slicer.

The Measure calculation in the Events table is as follows:

MeasureEventPeriod =

VAR Startdt = CALCULATE(MIN(Events[StartDate]), REMOVEFILTERS('Calendar'))

VAR Enddt = CALCULATE(MIN(Events[EndDate]), REMOVEFILTERS('Calendar'))

VAR EventPeriod = MIN('Calendar'[Date])>=Startdt && MIN('Calendar'[Date])<= Enddt

VAR Result = IF(EventPeriod, 1)

Return Result

If the slicer selected Department = A, I want to show Department A & Z 

If the slicer selected Department = B, I want to show Department B & Z 

If the slicer selected Department = A & B, I want to show Department A & B & Z 

If the slicer selected Department = Z, I want to show only Z 

Or the other option is to not show Z in the slicer but include them in the visual. Visual is a matrix with Department and Role as rows and Months and Weeks as Columns.

Since the measure only involves Calendar, I am not sure how to filter and show rows belonging to specific Department

Sample File with data is as below:

PBIX FIle Link