The "Everywhere" button actually selects the home directory, so use
an appropriate label ("My files") and add a "user-home" icon.
Pre-select the right button when entering search, depending on the location
where the "Find ..." action was triggered.
Add tooltips for both buttons, stating where to look for files. Most
importantly, this includes the full path for "From here".
Do not hide the buttons in case the url is non-local, as it is confusing:
1. The state depends on the previous search. When the user hits "Find"
when browsing e.g an SMB share, the search was probably in the home dir.
2. The current search location was hidden
3. The user may want to do a local search, give the option to do so.