I have 4 reports in the dashboard and want to use the 1st chart as a filter to filter the 2nd chart but don't want to impact the 3rd and 4th chart. How I can do this?

To do that just ignore the filter on the charts where you don’t want to apply filter. For example, if you don’t want to apply the filter on 3rd and 4th reports then just click on it and select ignore filter.