This bug report pertains to xfce4-screenshooter 1.8.2 run under Xubuntu 16.0.6 LTS, currently under a linux kernel 4.4.0-143-generic x86_64. It proposes an enhancement over the existing program. xfce4-screenshooter has an option -s which lets one specify the directory, where the screenshot file is stored. However, if this is used, a dialogue pops up to specify the file. The filename is already preset reasonably. In a German environment it is Bildschirmfoto_yyyy-mm-dd_hh-nn-ss.png where yyyy specifies the year mm specifies the month dd specifies the day hh specifies the hour nn specifies the minutes ss specifies the seconds. I propose to bypass the whole dialogue if the directory specification ends wiith /*, e.g. xfce4-screenshooter -cms ~/tmp/* should create the file with its default filename rightaway in ~/tmp (i.e. bypassing the store dialogue). This enhancement would enable chaining gimp by something like xfce4-screenshooter -fmd 4 -s ~/temp/* && gimp $(ls -1t ~/temp/*.png | head -n1) (thanks to Andre Miranda in his comment on https://bugzilla.xfce.org/show_bug.cgi?id=15237 for the principal idea) to circumvent snap-installed versions of gimp processing screenshots stored in /tmp. Another additional proposal is to let xfce4-screenshooter evaluate a dedicated environment variable (if it exists) to determine the default directory for the screenshot files.
As mentioned in that bug, since 1.9.4 it's possible to pass filepaths to the -s option, in your case it would be something like this: OUTPUT="/tmp/Bildschirmfoto_$(date +%F_%T).png"; xfce4-screenshooter -fmd 4 -s "$OUTPUT" && gimp "$OUTPUT"
Closing because since 1.9.4 this user case is supported, reopen if not.