Pressing the ESC key or double-clicking with the right mouse button anywhere in the window returns you to the previous directory comparison mode. This works only if the current file or subdirectory comparison has been selected from within a directory difference listing.
Started as another program’s diff viewer — with two paths on the
command line and no directory comparison behind the
current one — there is nothing to go back to. ESC then closes
Diffoniq, which is what a diff viewer called from git difftool or a
file manager is expected to do. While a search is active,
the first ESC only removes the match highlighting.