I see where you’re setting the filter, but I don’t see where you’re performing a query with the changed filter. Maybe you didn’t post that section of code?
When you apply your filter to the query for the repeater, you need to also apply the filter to the three functions that determine the counts. You will need to modify the code in the functions to apply the same filter as the query for the Repeater. You can call those three functions from from dropdown1_change() function.
You shouldn’t have the Repeater onItemReady() function in the dropdown1_change() function. The onItemReady() function is defined only once, in the onReady() function. The onItemReady() functions, is actually an event handler, which means once it’s defined (in the onReady function), it is triggered every time that the Repeater’s data changes.
You might want to look at this example which demonstrates changing the contents of a Repeater based on a dropdown and a search bar.