numbererd tabluarx inside tabulars

Question

I am generating tex documents automatically (HTML -> pandoc(tex) -> postprocess -> XELATEX), and my general table environment is tabularx (with usage of package ltablex, so these are longtables effectively).

One reason for this choice is the possibility to assign captions consistently (using package caption).

Sometimes need outer tabular's that should display the inner nested tabularx's with caption side-by-side.

My current result is: which is created with this file

\documentclass[a4paper,dvipsnames]{article}
\usepackage[ngerman]{babel}
\usepackage[paper=portrait,pagesize]{typearea}
\usepackage{color}
\usepackage[table]{xcolor}
\definecolor{tableHighlightRowBackground}{gray}{0.9375}
\definecolor{tablecaptionfontcolor}{RGB}{108, 117, 125}
\definecolor{arrayrulecolor}{RGB}{222,226,230}
\usepackage[most]{tcolorbox}
\usepackage{relsize}
\usepackage{ltablex}
\keepXColumns
\usepackage{multirow}
\usepackage{caption}
\DeclareCaptionFont{muted}{\color{tablecaptionfontcolor}}
\captionsetup[table]{singlelinecheck=false, justification=raggedleft, font={muted,small}}
\setlength\parindent{0pt}
\usepackage{booktabs}
\usepackage{colortbl}
\arrayrulecolor{arrayrulecolor}
\begin{document}
\begin{tabular}{@{}ll@{}}
\toprule
    \begin{minipage}[t]{0.47\columnwidth}\raggedright
    a
    \strut
    \end{minipage} 
& 
    \begin{minipage}[t]{0.47\columnwidth}\raggedright
    b

    \strut
    \end{minipage}
\tabularnewline
    \begin{minipage}[t]{0.47\columnwidth}\raggedright
        \begin{tabularx} {\textwidth} {Xcrr}
        \bfseries
        Position & \bfseries Year 2020 & \bfseries Year 2021 \
        \midrule
        \endhead
        \bottomrule
                \caption{Important Caption} \tabularnewline
        \endfoot
        \rowcolor{tableHighlightRowBackground} % this is another problem, this command applies the bg color to the complete outer row
        \bfseries A & { \bfseries 11,40 € } & { \bfseries 10,00 € } \
        \end{tabularx}
    \strut
    \end{minipage} 
& 
    \begin{minipage}[t]{0.47\columnwidth}\raggedright
    d
    \strut
    \end{minipage}\tabularnewline
\bottomrule
\end{tabular}
\end{document}

The desired output would be a caption below the inner tabularx (inside the outer tabular).

See this html-counterpart:

My framework is quite flexible, there is just one invariant: The inner tabularx should be displayed as full-width table with a table caption and number.

Answer 1

Here is my suggestion based on some assumptions on the desired output. I have not changed the inner tabular with respect to avoiding the repetition of \bfseries.

\documentclass{article}
%\usepackage{ltablex}
%\keepXColumns
\usepackage{tabularx}
\usepackage{multirow}
\usepackage{caption}
\usepackage{booktabs}
\usepackage[table]{xcolor}
\definecolor{tableHighlightRowBackground}{rgb}{0.8,0.8,0.8}
\begin{document}
\begin{tabular}{@{}p{0.9\textwidth}l@{}}
\toprule
a & b
\\
        {\begin{tabularx} {0.9\textwidth} {Xcrr}
        \bfseries
        Position & \bfseries Year 2020 & \bfseries Year 2021 \\
        \midrule
        \rowcolor{tableHighlightRowBackground} % this is another problem, this command applies the bg color to the complete outer row
        \bfseries A & { \bfseries 11,40 € } & { \bfseries 10,00 € } \\
        \bottomrule
        \end{tabularx}}
        \captionof{table}{Important Caption}
& 
d \\
\bottomrule
\end{tabular}
\end{document}