I am adding an accommadation booking system on my website and want to create a search bar as below, but i cannot find any button.
Hi,
You can build your own. Take a look at the tutorial How to Use Code to Let Your Users Search a Collection . This tutorial guides you through the steps needed to create simple version of what you need. You can use the code in the tutorial as a starting point, and then add the additional search components that you need.
Have fun,
Yisrael