I am currently using Document > Settings > Modules > Theorems (Numbered by Type within Sections) in Lyx.
However, I need my theorems/definitions to be numbered according to subsection instead. i.e.
2 Introduction
2.1 Subsection ...
Definition 2.1.1
Theorem 2.1.2
2.2 Subsection 2
Theorem 2.2.1
Additionally, I also want the text after the labels to be in a new line (instead of continuing after the bold text), i.e.
Definition 2.2.2
The definition of formula is...
I would also like to state that I am rather new to lyx so I am not familiar with editing TeX code (if required) in the editor so detailed steps would really be appreciated.
Thank you!
Edit 1: MWE (I removed mostly font related code)
% Preview source code
#LyX 2.2 created this file. For more info see http://www.lyx.org/
\lyxformat 508
\begin_document
\begin_header
\save_transient_properties true
\origin unavailable
\textclass article
\use_default_options true
\begin_modules
theorems-ams-bytype
theorems-sec-bytype
\end_modules
\maintain_unincluded_children false
\graphics default
\default_output_format default
\output_sync 0
\bibtex_command default
\index_command default
\paperfontsize default
\spacing single
\use_hyperref false
\papersize default
\use_geometry false
\use_package amsmath 1
\use_package amssymb 1
\use_package cancel 1
\use_package esint 1
\use_package mathdots 1
\use_package mathtools 1
\use_package mhchem 1
\use_package stackrel 1
\use_package stmaryrd 1
\use_package undertilde 1
\cite_engine basic
\cite_engine_type default
\biblio_style plain
\use_bibtopic false
\use_indices false
\paperorientation portrait
\suppress_date false
\justification true
\use_refstyle 1
\index Index
\shortcut idx
\color #008000
\end_index
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\paragraph_indentation default
\quotes_language english
\papercolumns 1
\papersides 1
\paperpagestyle default
\tracking_changes false
\output_changes false
\html_math_output 0
\html_css_as_file 0
\html_be_strict false
\end_header
\begin_body
\begin_layout Standard
\noindent
\begin_inset CommandInset toc
LatexCommand tableofcontents
\end_inset
\end_layout
\begin_layout Standard
\paragraph_spacing onehalf
\noindent
\begin_inset Newpage newpage
\end_inset
\end_layout
\begin_layout Section
\paragraph_spacing onehalf
\noindent
Title
\series bold
1
\begin_inset ERT
status open
\begin_layout Plain Layout
\backslash
numberwithin{equation}{section}
\end_layout
\end_inset
\begin_inset ERT
status open
\begin_layout Plain Layout
\backslash
setlength{
\backslash
parindent}{1.5pt}
\end_layout
\end_inset
\end_layout
\begin_layout Section
\paragraph_spacing onehalf
\noindent
Title 2
\end_layout
\begin_layout Subsection
\paragraph_spacing onehalf
\noindent
Sub 1
\end_layout
\begin_layout Subsection
\paragraph_spacing onehalf
\noindent
Sub 2
\end_layout
\begin_layout Definition
\noindent
My first definition
\end_layout
\end_body
\end_document