Angular - Checkbox unique selection

In my project I have created Select/ Unselect Checkbox functionality. There are multiple different checkbox on same page. How can I separate Select All Checkbox functionality so that its only applied to its values.

Demo Video - https://screenrec.com/share/uBJLD9yXkZ Select All should only select Data 1 and Data 2 of 1st Checkbox, not second and vice versa

Demo code https://stackblitz.com/edit/angular-material-select-all-bx4qen?file=src%2Fapp%2Fapp.component.html