%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-7-22 on page II-556 in "Document divisions".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{159.0pt}

%  Use biber program
\makeatletter
\renewcommand\section{\@startsection{section}{1}{\z@}%
                                    {-1.25ex \@plus-1ex \@minus-.2ex}%
                                    {.5ex}%
                                    {\normalfont\normalsize\bfseries}}
\makeatother
\setlength\parindent{0pt}

%StartShownPreambleCommands
\usepackage[style=authoryear,
            dashed=false]{biblatex}
\addbibresource{tlc-ex.bib}
%StopShownPreambleCommands

\begin{document}
\newrefsegment
\ldots\ \cite{smith2020-1} \ldots

\printbibliography
  [title=References of refsegment 1, segment=1]

\newrefsegment
\ldots\ \cite{smith2020-2} \ldots

\printbibliography
  [title=References of refsegment 2, segment=2]

\printbibliography[title=Global bibliography]
\end{document}