How to write sign like that pic

Here's a possibility. You should be more precise about what the symbol is used for.

\documentclass{article}
\usepackage{amsmath}

\newcommand{\fourcircles}{%
  \mathrel{%
    \tfrac{\,{\circ}\,{\circ}\,}{\raisebox{0.25\height}{$\scriptstyle{\circ}\,{\circ}$}}%
  }%
}

\begin{document}

$a\fourcircles b$

\end{document}

With smaller circles:

\documentclass{article}
\usepackage{amsmath}

\newcommand{\fourcircles}{%
  \mathrel{%
    \tfrac{\scriptscriptstyle\,{\circ}\,{\circ}\,}
          {\raisebox{0.75\height}{$\scriptscriptstyle{\circ}\,{\circ}$}}%
  }%
}

\begin{document}

$a\fourcircles b$

\end{document}

I made it \mathrel, but that can be changed. Automatically works across math styles. Same height as + sign.

\documentclass{article}
\usepackage{scalerel,tabstackengine}
\newcommand\mysym{\mathrel{\scalerel*{\ensurestackMath{\setstackgap{S}{0pt}%
  \Shortstack{\circ\circ\\{-}\!\!{-}\!\!{-}\\\circ\circ}}}{+}}}
\begin{document}
$a\mysym b+c$

$\scriptstyle a\mysym b+c$

$\scriptscriptstyle a\mysym b+c$
\end{document}

Here's a version that better matches the rule thickness

\documentclass{article}
\usepackage{scalerel,tabstackengine}
\newcommand\mysym{\mathrel{\scalerel*{\ensurestackMath{\setstackgap{S}{3pt}%
  \Shortstack{\circ\,\circ\\\rule[.5pt]{1.7em}{1pt}\\\circ\,\circ}}}{+}}}
\begin{document}
$a\mysym b+c$

$\scriptstyle a\mysym b+c$

$\scriptscriptstyle a\mysym b+c$
\end{document}

Like this?

This geometer symbol can be draw as small picture: pic and can be positioned anywhere on map's lines:

\documentclass[tikz, margin=3mm]{standalone}

\begin{document}
    \begin{tikzpicture}[
          dot/.style = {circle, draw, semithick, fill=white, outer sep=2mm,
                        node contents={}},
pics/progress/.style = {code = {\node[dot,above left];
                                \node[dot,above right];
                                \node[dot,below left];
                                \node[dot,below right];}
                        }
                        ]
\draw[very thick] (0,0) -- ++ (2,0) pic [pos=0.6] {progress};
    \end{tikzpicture}
\end{document}