# Reference from a different folder

I'm writing my thesis and have trouble reference labels between chapters. My main folder look like this:

• Main Folder, where I have the main tex file and folders where I have the main tex file and folders

1. main tex file, where the documentclass, userpackage, etc are located. With the \makechapter{The First Chapter} \input{Chapter1/chapter1.tex}
\makechapter{The Second Chapter} \input{Chapter2/chapter2.tex}
2. Chapter1 (Folder, where inside the file i write in)
chapter1.tex
3. Chapter2 (Folder, where inside the file i write in)
chapter2.tex

When I write in chapter1.tex

\section(Chapter One) \label(Ch1)
\begin{equation} \label{eq:1}
a^2 + b^2 = c^2
\end{equation}


How can I in chapter2.tex file, reference the labels in chapter1, which is located in a file located in another folder?, for example when I write in chapter2.tex,
As equation \lable(eq:1) in chapter \lable(Ch1) show.

Because now it just shows [??]

Technically, this should work (if not, post your MWE). See the following MWE.

main.tex

   documentclass[12pt,a4paper]{book}

\begin{document}

\input{ch1/ch1.tex}
\input{ch2/ch2.tex}

\end{document}


now, ch1.tex

\chapter{ch1}
\begin{equation}
\label{eq:1}
x= x \,
\end{equation}


and ch2.tex

\chapter{ch2}
\begin{equation}
\label{eq:2}
x= x \,
\end{equation}

Eq.~\ref{eq:1} ...


produces, following ---
{"ft_lang_label":"__label__en","ft_lang_prob":0.84454715,"math_prob":0.7993782,"size":1058,"snap":"2021-31-2021-39","text_gpt3_token_len":287,"char_repetition_ratio":0.17741935,"word_repetition_ratio":0.28,"special_character_ratio":0.24858223,"punctuation_ratio":0.14975846,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9996878,"pos_list":[0,1,2],"im_url_duplicate_count":[null,4,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-07-28T21:18:25Z\",\"WARC-Record-ID\":\"<urn:uuid:cf4de187-37e2-487f-9dc5-15c5372cac1f>\",\"Content-Length\":\"165467\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:24432644-c5db-4c76-a998-2631cd6ce415>\",\"WARC-Concurrent-To\":\"<urn:uuid:5cb02d1e-fa20-416b-b1a0-3b37cfc4b73f>\",\"WARC-IP-Address\":\"151.101.193.69\",\"WARC-Target-URI\":\"https://tex.stackexchange.com/questions/312646/reference-from-a-different-folder\",\"WARC-Payload-Digest\":\"sha1:TY4B5ODIULRIAAMDSZBZSSVZO2TS66ZD\",\"WARC-Block-Digest\":\"sha1:YBAZYPCJTYB3ESJRSKKMI34VTQB57M4W\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-31/CC-MAIN-2021-31_segments_1627046153791.41_warc_CC-MAIN-20210728185528-20210728215528-00206.warc.gz\"}"}