How to filter and show only selected items in datagridview?

I have a datagridview and recently I got task to add a checkbox column (which I did) and a button (btnFilter) that will filter/show only selected rows so for example if I check only 4th, 5th and 6th row and click on 'btnFilter' the datagridview would show only rows 4,5 and 6.

So, the problem is how to show only selected (checkbox) rows.

Thank you for your time.