\begin{table}
\centering
\begin{tblr}[         %% tabularray outer open
]                     %% tabularray outer close
{                     %% tabularray inner open
colspec={Q[]Q[]Q[]Q[]Q[]Q[]},
hline{2}={1-2}{solid, black, 0.05em},
hline{3}={1}{solid, black, 0.05em},
hline{4}={1-6}{solid, black, 0.05em},
hline{2}={4,6}{solid, black, 0.05em, l=-0.5},
hline{3}={4,6}{solid, black, 0.05em, l=-0.5},
hline{3}={3}{solid, black, 0.05em, l=-0.5, r=-0.5},
hline{2}={3,5}{solid, black, 0.05em, r=-0.5},
hline{3}={2,5}{solid, black, 0.05em, r=-0.5},
hline{1}={1-6}{solid, black, 0.1em},
hline{5}={1-6}{solid, black, 0.1em},
cell{1-2}{2}={}{halign=c},
cell{1-2}{3}={}{halign=c},
cell{1-2}{4}={c=2}{halign=c},
cell{1-2}{5}={}{halign=c},
cell{1-2}{6}={}{halign=c},
cell{1}{1}={c=3}{halign=c},
cell{2}{1}={c=2}{halign=c},
}                     %% tabularray inner close
A &  &  & B &  & C \\
X &  & Y & Z &  & W \\
1 & 2 & 1 & 1 & 2 & W \\
1 & 2 & 3 & 4 & 5 & 6 \\
\end{tblr}
\end{table} 
