The following code uses etoolbox to patch \@chapter, adding a "chapter ornament" to the LoF immediately after the default space (of 10\p@ that is usually added). You can change the code of \lofchapter to suit your ornament needs.

\documentclass{report}
\usepackage{lipsum}
\usepackage{etoolbox}
\makeatletter
% Update \@chapter to insert the chapter ornament in the LoF
\patchcmd{\@chapter}% <cmd>
{\addtocontents{lof}{\protect\addvspace{10\p@}}}% <search>
{\addtocontents{lof}{%
\protect\addvspace{10\p@}% Default space between chapters in LoF
\protect\lofchapter{\thechapter}% Add chapter ornament
}}% <replace>
{}{}% <success><failure>
\makeatother
\newcommand{\lofchapter}[1]{%
\noindent
\rule[.5ex]{.4\linewidth}{.2ex}\hfill
\textsc{Chapter #1}\hfill
\rule[.5ex]{.4\linewidth}{.2ex}\par
\nobreak
}
\begin{document}
\sloppy% Just for this example
\listoffigures
\chapter{First chapter}
\lipsum[1-10]\begin{figure}\caption{First figure}\end{figure}
\lipsum[11-20]\begin{figure}\caption{Second figure}\end{figure}
\lipsum[21-30]\begin{figure}\caption{Third figure}\end{figure}
\lipsum[31-40]\begin{figure}\caption{Last figure}\end{figure}
\lipsum[41-50]
\chapter{Second chapter}
\lipsum[1-10]\begin{figure}\caption{First figure}\end{figure}
\lipsum[11-20]\begin{figure}\caption{Second figure}\end{figure}
\lipsum[21-30]\begin{figure}\caption{Third figure}\end{figure}
\lipsum[31-40]\begin{figure}\caption{Last figure}\end{figure}
\lipsum[41-50]
\chapter{Third chapter}
\lipsum[1-10]\begin{figure}\caption{First figure}\end{figure}
\lipsum[11-20]\begin{figure}\caption{Second figure}\end{figure}
\lipsum[21-30]\begin{figure}\caption{Third figure}\end{figure}
\lipsum[31-40]\begin{figure}\caption{Last figure}\end{figure}
\lipsum[41-50]
\chapter{Last chapter}
\lipsum[1-10]\begin{figure}\caption{First figure}\end{figure}
\lipsum[11-20]\begin{figure}\caption{Second figure}\end{figure}
\lipsum[21-30]\begin{figure}\caption{Third figure}\end{figure}
\lipsum[31-40]\begin{figure}\caption{Last figure}\end{figure}
\lipsum[41-50]
\end{document}
\documentclassyou're using and packages associated with your LoF. It's obvious you're doing some additions since the default behaviour does not include the wordFigurebefore every number. Can you do this? – Werner May 14 '20 at 16:51