Inorder to enable regional language searching the following file need to be modofied.
sudo gedit /etc/koha/zebradb/etc/default.idx
comment the line "charmap word-phrase-utf.chr" ( Put # mark at the beginning of the line)
add the following line after the commented line
"icuchain words-icu.xml "
Rebuild the Zebra index
sudo koha-rebuild-zebra -v -f library
sudo gedit /etc/koha/zebradb/etc/default.idx
comment the line "charmap word-phrase-utf.chr" ( Put # mark at the beginning of the line)
add the following line after the commented line
"icuchain words-icu.xml "
Rebuild the Zebra index
sudo koha-rebuild-zebra -v -f library