Hi Pranav,
Yes, you can perform the calculation on one value of a variable by using the filter function in calculate function.
For suppose you want to calculate the average profit for only Technology category then you can create a measure as,
AVG Cat tech = CALCULATE(AVERAGE(Orders[Profit]),Orders[Category]="Technology")
If you add a slicer it would disturb all the tables and visuals in the sheet.
Hope it helps