find ~ -type d -name 'public_html' -exec cp ~/optimaservis.ru/public_html/yamochnyi-remont/index.php {} \;
или как тут
find ./*/public_html/fonari-signalnye/ -name ".main-section_adaptive.menu.php" | xargs -n 1 cp ~/mtest/public_html/fonari-signalnye/.main-section_adaptive.menu.php