Currently, awesomebar allows to search in different places by place symbols in it. I suggest to allow to select range of search. Example could be search engine or history, bookmark, tabs. User could switch category by moving left/right. Default would be all. When move left/right, enter will add search criterion with typed word.
For example I type google.com. Move right (history), right (tabs), pres enter, press enter and Firefox will switch to tab, where I have google.com opened. After single enter press on tab (so criterion was added), Firefox will show in awesomebar more than one options, so (for example) tab google.com and tab google.com/?q=Mozilla.