Kakoune provides the ctags.kak script, but this won't work with out of the box ctags from sourceforge.net. It relies on the readtags command that is available in universal-ctags, but not installed by default. The easiest way would be to use ctags from http://github.com/universal-ctags/ctags which will install the readtags command.

Search for tags file

Use the following hook to search for a tags file in the current directory, then parent directories, until found or the home or root directory is reached.

hook global KakBegin .* %{
    evaluate-commands %sh{
        path="$PWD"
        while [ "$path" != "$HOME" ] && [ "$path" != "/" ]; do
            if [ -e "./tags" ]; then
                printf "%s\n" "set-option -add current ctagsfiles %{$path/tags}"
                break
            else
                cd ..
                path="$PWD"
                # Replace any instances of repeated '/' with a single '/'
                path=`echo "$path" | tr -s /`                                   
            fi
        done
    }
}

This is equivalent to vim's :set tags=./tags; option.

Key mappings

This makes C-] look up the symbol under the cursor, similarly to vim:

map global normal <c-]> <a-i>w:ctags-search<ret>

Use C-o as usual to go back.