Hi @AliB. I’m not sure to which video you are referring, but in any case, perhaps the “Fix Incorrect Totals” DAX Pattern post might help.
Fix Incorrect Totals - DAX Patterns - Enterprise DNA Forum
If you still have issues, please upload your work-in-progress PBIX, your dataset, and a marked-up screenshot or Excel mockup of the visual you are having issues with for the forum members to analyze.
Greg