Click on Home/File explorer.

It will open a tab named "Resources". 

Select "Resources" in tree.

Click on "Search" button, that opens a "Search tab" with "Resources" context. 

 If user wants to change context of search, he needs to : 

1. Select node in the tree
2. Click a new time on "Search" button in the ribbon.

On image below, context has changed to "Common resources to all sites". 

=> Is it possible to change search context without having to click a new time on "Search" button in the ribbon. (Change the context each time a new node is selected in tree).