Count Choices (optionset) field

Hello

I am new to powerBI and so go easy on me 😉 I am sure this would have been asked before so if someone could point me in the right direction, it would be greatly appreciated.

I have a choices field on a dynamics 365 case (incident) form. The user creating the case can select multiple options from this choice (optionset) field. I want to create a report that gives me totals on each option that have been assigned to cases.

The choices field stores all the selected options in one column seperated by a comma.  I have created a table with each choice label, its ID and option name and linked it back to the cases table.

Where I am stuck is what to do with the cases Choice field to be able to count the total options selected for period.  Do I need to seperate each case option out into its own field, assign a number (like 1) to it to then be able to count all the numbers in the field/column?  Or could I just use a filter to count the options within the one field dynamically in the PowerBI report?

I hope this makes sense, many thanks in advance for any suggestions you are able to offer.