@Baharul Islam Thanks for reaching out. Your CORN can only have one expression. So you need to create multiple logic apps/function app (15 different logic apps) with different CORN expressions as per your requirements. Within each logic app, you will be calling your main logic app (HTTP trigger or as per your need) and passing different values for the different scenarios from the calling logic app as per your requirement.
In case if you are using the function app then you can create a single cron expression that represents the biggest common denominator among all the 15 different times and make the function intelligent enough to decide if it should skip or serve the trigger with what values. I will not suggest this approach as it may be triggering your function app in a scenario where you don't want to do anything and may take more effort to create the logic and cost more than the individual function/logic app if the time of execution is different for all the CORN expressions.