Power BI has a few built in ways to make a % of total in a table. I showcase those and how to write out more complex examples using DAX for % of grand total as well as % of parent total.
After showing the built in formula free method, I explain the ALL function inside CALCULATE to get the denominator, then I show using DIVIDE to get the %. I then show ALLSELECTED.
% with filters=DIVIDE(Measure,CALCULATE( Measure, ALLSELECTED(Table to show all of)))*100
I also show the % of parent total which uses combines uses =IF(ISFILTERED(parent...) and returns different outputs depending. I showcase my face in this video, just trying something out, let me know if you like it!
Example files can be found here: www.xlconsulting-asia.com/youtube-files
00:00 - % of total
04:42 - % of parent total