MacOS – Why doesn’t spotlight return this file

If you're comfortable opening the terminal you could run the command

locate ABC/readme.txt

and it will give you the full file path to any files on your machine that are named readme.txt in a folder named ABC.

While you're there you can copy and past the path as an argument to the open command and it will open it for you.

Taking it one step further you can use the output of locate as the arguments for open with xargs

locate ABC/readme.txt | xargs open

Will open all files that have ABC/readme.txt on your machine just as if you had double-clicked them.

You can use the find command to show you the target of the symlink then have awk throw away the rest of the line. Then wrap that in a loop that tells you what it's doing then feeds the names to mdimport:

for linktarget in $(find ${HOME} -type l -ls | awk -F'-> ' '{print $NF}'); do
    echo "importing ${linktarget}"
    mdimport "${linktarget}"; 
done

It's probably easier to cut and paste this little script since there are some spaces that are easy to miss. (like the one after the arrow in the awk statement).