Is it possible to have a sort of resource filter on the calendar?

You can start with the following tutorial which displays a resources calendar similar to yours (time on the vertical axis, resources/providers on the horizontal axis):

• JavaScript Resource Calendar Tutorial - PHP/MySQL (Open-Source)

If you only want to display selected columns, you can modify the backend_resources.php script (the API endpoint that returns the resources) to accept a list of resources in the query string and just return the data for them. You can do something similar for the event data.

To select the resources, you can use a set of checkboxes or any other UI element that support selecting multiple values.

You can also filter the values on the client side:

1. Let’s say you have a list of all resources:

const columns = [
  { name: "Kamran Kamali", id: 1 },
  // ...
];

2. When you change the selection, you need to filter the data as needed:

const visibleColumns = columns.map(c => {
  return shouldBeIncluded(c));
});

3. Now you can display the filtered column list:

calendar.update({columns: visibleColumns);