We have a search form in a sidebar that currently looks like this:
Now, we'd like to add an option to this to let the user choose whether he wants to search the entire site, or only the section he's in at the moment.
The orange line behind is a line over the whole page, it emphasizes the sidebar. Because of this it's not possible to put a checkbox or toggle button below the search bar (or we'd have to put the whole form in a fieldset and draw an orange border around, which we'd rather not).
I was thinking of adding a second button to the form, next to the search button. This button would select the option. The behaviour of the search button wouldn't change, but the extra button selects whether you search in the whole site or this particular section.
So I was thinking of using an expressive icon with a tooltip - but the best would be to use an icon which is already clear in itself. Either the icon should change when a different option is selected, or the button could have a different background as if it were pushed in when one of the options is selected.
However, I can't come up with a good idea for an expressive icon for this, and also I can't find anything like this in fontawesome or glyphicons. It seems impossible to capture this rather complicated meaning in an icon, and the fact that there's no 'standard' (as for settings icons, for example) makes this solution also difficult.
Is there another way we could make this option clear to users without breaking the current sidebar layout?