Here you can setup the filters for your heatmap. You have a lot of different things you can change, so that you get the specific filter you want. When you start changing the different elements in the filter you can apply that fitler. It will always say how many games it will show with the filter you have applied.
So you can e.g set a filter to show Home players, male and female from 01-01-2019 to 01-01-2020 and on a specific guide.