How to use the full textwidth for tablenotes under multiple tables?

Question

When i use multiple tables or also in the case of subtables and want to include one tablenote which describes all tables simultaneously the tablenote is only created for the left table not using the whole textwidth. How can i make a tablenote making use of the whole text width?

\documentclass[11pt,a4paper]{article}

\usepackage[flushleft]{threeparttable}
\usepackage{booktabs}
\usepackage{a4wide}

\begin{document}

    \begin{table}[!htbp]
        \begin{threeparttable}
            \parbox{.553\linewidth}{
                \centering
                \caption{test1}
                \setlength\tabcolsep{0pt}
                \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l  r  r  r  r  r  r  }
                    \toprule
                    test & test & test & test & test & test & test \\ 
                    \midrule 
                    test & 0 & 0 & 0 & 0 & 0 & 0 \\ 
                    \bottomrule
                \end{tabular*}
            }
            \hfill
            \parbox{.443\linewidth}{
                \centering
                \caption{test2}
                \setlength\tabcolsep{0pt}
                \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l  r  r  r  }
                    \toprule
                    test & test & test & test  \\ 
                    \midrule
                    test & 0 & 0 & 0 \\ 
                    \bottomrule 
                \end{tabular*}
            }
            \begin{tablenotes}
                \item{\textit{Notes:}} test test test test test test test test test test test test test test
            \end{tablenotes}
        \end{threeparttable}
    \end{table}

\end{document}

Answer 1

without use of \parbox:

\documentclass[11pt,a4paper]{article}
\usepackage[showframe]{geometry}

\usepackage[flushleft]{threeparttable}
\usepackage{array, booktabs}

\begin{document}

\begin{table}[!htbp]
    \begin{threeparttable}
    \centering
    \setlength\tabcolsep{0pt}
    \begin{tabular*}{\linewidth}{p{0.54\textwidth}
                                 @{\extracolsep{\fill}}
                                 p{0.44\textwidth}}
        \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l *{6}{r}}
            \toprule
            test & test & test & test & test & test & test \\
            \midrule
            test & 0 & 0 & 0 & 0 & 0 & 0 \\
            \bottomrule
        \end{tabular*}
        &
        \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l *{3}{r}}
            \toprule
            test & test & test & test  \\
            \midrule
            test & 0 & 0 & 0 \\
            \bottomrule
        \end{tabular*}%
        \end{tabular*}
        \begin{tablenotes}
            \item{\textit{Notes:}} test test test test test test test test test test test test test test
        \end{tablenotes}
    \end{threeparttable}
\end{table}
\end{document}

Answer 2

threeparttable hooks into tabular to get the width. So imho a logical way would be to use a surrounding tabular:

\documentclass[11pt,a4paper]{article}

\usepackage[flushleft]{threeparttable}
\usepackage{booktabs}
\usepackage{a4wide}

\begin{document}

\begin{table}[!htbp]
    \begin{threeparttable}
    \begin{tabular}{@{}l@{}}
        \parbox{.553\linewidth}{
            \centering
            \setlength\tabcolsep{0pt}
            \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l  r  r  r  r  r  r  }
                \toprule
                test & test & test & test & test & test & test \\
                \midrule
                test & 0 & 0 & 0 & 0 & 0 & 0 \\
                \bottomrule
            \end{tabular*}
        }
        \hfill
        \parbox{.443\linewidth}{
            \centering
            \setlength\tabcolsep{0pt}
            \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}l  r  r  r  }
                \toprule
                test & test & test & test  \\
                \midrule
                test & 0 & 0 & 0 \\
                \bottomrule
            \end{tabular*}
        }
        \end{tabular}

        \begin{tablenotes}
            \item{\textit{Notes:}} test test test test test test test test test test test test test test
        \end{tablenotes}
    \end{threeparttable}
\end{table}

\end{document}