How can i change the shipping to field

[bassel.93]

Hello guys

i am from belgium and when everytime i try to find an item to buy i see that it couldn't get shipped to belgium

so i needed to change the search settings into  a belgium shipping only

but i couldn't reach it 

i've opened advanced button on the right of search button but i couldn't know how to reach that operation

so please give me a step by step details by how to change it .. 

THNX ALL