Vtgyjfy

I know that there are some amazingly talented tikz-guys here! I am looking for something like this:

And this is about as far as I came, how to properly align a matrix with 5 columns within the 4 columns of the upper matrix...?

documentclass[tikz,border=3.14mm]{standalone}

usetikzlibrary{shapes,arrows}

usetikzlibrary{matrix}



begin{document}

  begin{tikzpicture}

  matrix (M) [matrix of nodes,

  nodes={minimum height = 7mm, minimum width = 1.2cm, outer sep=0, anchor=center, draw},

  column 1/.style={nodes={draw=none}, minimum width = 4cm},

  row sep=1mm, column sep=-pgflinewidth, nodes in empty cells,

  e/.style={fill=green!10}, f/.style={fill=blue!10}

  ]

  {

    1: & |[e]| & & & & \

    2: & & |[e]| & & & \

    3: & & & |[e]| & & \

    4: & & & & |[e]| & \

    5: & & & & & |[e]| \

  };



  node [above of= M-1-2, node distance = 3.5em, rotate=90] () {Test1 }; 

  node [above of= M-1-3, node distance = 3.5em, rotate=90] () {Test2}; 

  node [above of= M-1-4, node distance = 3.5em, rotate=90] () {Test3}; 

  node [above of= M-1-5, node distance = 3.5em, rotate=90] () {Test4}; 

  node [above of= M-1-6, node distance = 3.5em, rotate=90] () {Test5}; 



  draw (M-5-2.south west) coordinate (LT) edge[|<->|, >= latex] node[below, node distance = 4em]{Total number of datasets} (LT-|M-5-6.south east);

  end{tikzpicture}

end{document}

You have already done all the hard work. One only needs to multiply some of the dimensions by 4/5=0.8 to arrive at

documentclass[tikz,border=3.14mm]{standalone}

usetikzlibrary{matrix,fit,decorations.pathreplacing}



begin{document}

  begin{tikzpicture}

  matrix (M) [matrix of nodes,

  nodes={minimum height = 7mm, minimum width = 1.2cm, outer sep=0, anchor=center, draw},

  column 1/.style={nodes={draw=none}, minimum width = 4cm},

  row sep=1mm, column sep=-pgflinewidth, nodes in empty cells,

  e/.style={fill=green!10}, f/.style={fill=blue!10}

  ]

  {

    1: & |[e]| & & & & \

    2: & & |[e]| & & & \

    3: & & & |[e]| & & \

    4: & & & & |[e]| & \

    5: & & & & & |[e]| \

  };



  node [above of= M-1-2, node distance = 3.5em, rotate=90] () {Test1 }; 

  node [above of= M-1-3, node distance = 3.5em, rotate=90] () {Test2}; 

  node [above of= M-1-4, node distance = 3.5em, rotate=90] () {Test3}; 

  node [above of= M-1-5, node distance = 3.5em, rotate=90] () {Test4}; 

  node [above of= M-1-6, node distance = 3.5em, rotate=90] () {Test5}; 



  draw (M-5-2.south west) coordinate (LT) edge[|<->|, >= latex] node[below, node distance = 4em]{Total number of datasets} (LT-|M-5-6.south east);

  node[fit=(M-5-2) (M-5-5),yshift=-0.6cm,inner sep=0pt](F){};

  draw[thick,decorate,decoration=brace] (F.south east) -- (F.south west);

  matrix (M') [anchor=north west,matrix of nodes,

  nodes={minimum height = 7mm, minimum width = 0.8*1.2cm, outer sep=0, anchor=center, draw},

  column 1/.style={nodes={draw=none},},

  row sep=1mm, column sep=-pgflinewidth, nodes in empty cells,

  ] 

  at ([yshift=-1cm,xshift=0.2*1.2cm]M.south west)

  {1: & x& x & x & x & x\ 

   2: & x& x & x & x & x\ 

   3: & x& x & x & x & x\ 

   4: & x& x & x & x & x\ };

  end{tikzpicture}

end{document}

One possibility is to do the hard-coded positioning as in:

documentclass[tikz,border=3.14mm]{standalone}

usetikzlibrary{shapes,arrows}

usetikzlibrary{matrix, positioning}

usetikzlibrary{patterns, decorations.pathreplacing}

tikzstyle{overbrace style}=[decorate,decoration={mirror, brace,raise=0.5cm}]

begin{document}

  begin{tikzpicture}

  matrix (M) [matrix of nodes,

  nodes={minimum height = 7mm, minimum width = 1.2cm, outer sep=0, anchor=center, draw},

  column 1/.style={nodes={draw=none}, minimum width = 4cm},

  row sep=1mm, column sep=-pgflinewidth, nodes in empty cells,

  e/.style={fill=green!10}, f/.style={fill=blue!10}

  ]

  {

    1: & |[e]| & & & & \

    2: & & |[e]| & & & \

    3: & & & |[e]| & & \

    4: & & & & |[e]| & \

    5: & & & & & |[e]| \

  };



  node [above of= M-1-2, node distance = 3.5em, rotate=90] () {Test1 }; 

  node [above of= M-1-3, node distance = 3.5em, rotate=90] () {Test2}; 

  node [above of= M-1-4, node distance = 3.5em, rotate=90] () {Test3}; 

  node [above of= M-1-5, node distance = 3.5em, rotate=90] () {Test4}; 

  node [above of= M-1-6, node distance = 3.5em, rotate=90] () {Test5}; 

    node[below = 0 cm of M-5-4.south west] (A) {};

  draw (M-5-2.south west) coordinate (LT) edge[|<->|, >= latex] node[below, node distance = 4em]{Total number of datasets} (LT-|M-5-6.south east);

 draw [overbrace style] (M-5-2.south west) -- (LT-|M-5-6.south east);

 node[below = 0.5 cm of A] (B) {};

 matrix (M2) [below = 0cm of B,matrix of nodes,

 nodes={minimum height = 7mm, minimum width = 1.2cm, outer sep=0, anchor=center, draw},

 column 1/.style={nodes={draw=none}, minimum width = 4cm},

 row sep=1mm, column sep=-pgflinewidth, nodes in empty cells,

 e/.style={fill=green!10}, f/.style={fill=blue!10}

 ]

 {

    1: & |[e]| & & & & \

    2: & & |[e]| & & & \

    3: & & & |[e]| & & \

    4: & & & & |[e]| & \

    5: & & & & & |[e]| \

 };



 node [above of= M-1-2, node distance = 3.5em, rotate=90] () {Test1 }; 

 node [above of= M-1-3, node distance = 3.5em, rotate=90] () {Test2}; 

 node [above of= M-1-4, node distance = 3.5em, rotate=90] () {Test3}; 

 node [above of= M-1-5, node distance = 3.5em, rotate=90] () {Test4}; 

 node [above of= M-1-6, node distance = 3.5em, rotate=90] () {Test5}; 



 draw (M-5-2.south west) coordinate (LT) edge[|<->|, >= latex] node[below, node distance = 4em]{Total number of datasets} (LT-|M-5-6.south east);

  end{tikzpicture}

end{document}

which would yield you: