switch focus between widget area and view area

[dassio]

i am using similarity tool, after i found the duplicates, i want to review all of them. my workflow will be:

choose one item from similarity  sidebar ---> remove some duplicate in the view area --> go back to similarity side bar, choose next item ---> switch to view area again  ...

now , the switch between sidebar area and view area has to be done with mouse, anyway i can assign an shortcut to it ?