How to Customize a Button to Display a Selection Page

[lj4353]

I have a page with a "contacts Link Multiple" field. In the standard functionality, there is a "V" button next to the contacts field. When clicked, it displays a selection page for contacts.

Now, I want to create a button at the top right of the details page. After clicking it, I want it to behave the same way as the "V" button. Are there any reference examples for this?