```ts
// YourComponent.stories.ts

import { Story, Meta } from '@storybook/angular/types-6-0';
import YourComponent from './your.component';

// a function to apply some computations
const someFunction = (valuePropertyA: string, valuePropertyB: string) => {
  // makes some computations and returns something
};

export default {
  component: YourComponent,
  title: 'A complex case with a function',
  // creates specific argTypes with options
  argTypes: {
    propertyA: {
      control: {
        type: 'select',
        options: ['Item One', 'Item Two', 'Item Three']
      },
    },
    propertyB: {
      control: {
        type: 'select',
        options: ['Another Item One', 'Another Item Two', 'Another Item Three']
      },
    },
  },
} as Meta;

const Template: Story<YourComponent> = (args: YourComponent) => {
  const { propertyA, propertyB } = args;

  const someFunctionResult = someFunction(propertyA, propertyB);

  args.someProperty = someFunctionResult;
  return {
    component: YourComponent,
    props: {
      ...args,
      someProperty:someFunctionResult
    },
  };
};
```