Pretty much the same as the Open As Root. Navigate to
Create a new file called
Open that newly created file in your favourite editor and post the following:
[Desktop Entry] Type=Action Tooltip=Open Terminal Name=Open Terminal Profiles=profile-one; Icon=utilities-terminal [X-Action-Profile profile-one] MimeTypes=inode/directory; Exec=termite -w %f Name=Default profile
Exec section to whatever your preferred terminal app is.
Reopen PCmanFM and boom, open terminal here.
Failing that, use F4