KPI -Dax

Hi team, 
I need your help to achieve this task:

Requirement:

I have one slicer called source(Which contains different sources and type is text)
Based on that source I created one KPI, a Distinct count of the source

the actual requirement is :

If the Source filter is not selected, it should show The KPI which I created (source distinct count)
But if the user selects any one source, it should show the source name which the user selected
Output excepting :
Scenario 1: If the source is not filtered(like the above image) the output describing #source 5(Distinct count of all sources)
Scenario 2: If the source is selected (Eg: From source slicer user selected analytics text value) so in that case instead of shoeing distinct count, it should show the selected source name, so here output is 
Analytics(instead of scenario 1 output)


Thanks 
Alan