Add \resetparts

main.tex

@@ -16,6 +16,8 @@
   \let\bibcloseparen=\bibclosebracket%
 }
 
+\usepackage{bookmark} % Manage bookmarks
+
 \usepackage[draft, defaultColor=BlueViolet, xcolor=dvipsnames]{changes} % Track changes
 
 \usepackage{enumitem} % Customise lists
@@ -70,6 +72,10 @@
     \vspace*{0.5cm}%
 }
 
+\newcommand*{\resetparts}{% End the parts in TOC to set chapters at the root level
+    \bookmarksetup{startatroot}%
+}
+
 %% Document
 \begin{document}