In your Data Collection you should only have ONE field called courseDate which will be your date value for the different courses. Then you just use the code as above and set that element on the page to that items courseDate. You should not have fields in a Data Collection with like dateOne, dateTwo and so on.
If you have then create a new Data Collection that is connected to your courses Data Collection that is called CourseEvents and with a reference to the Courses Data Collection and in this one you enter the date, time, duration, price and that information that will be different for every date or could be different.
Then when you use the repeater connected you filter out the CourseEvents when you have selected the course you want to see events connected to. Easy and clean.