Serverless shared layers(node_modules) for all lambdas in multiple services - node.js

Question

I have current structure for the project below:
project/
├── node_modules
├── services
└── service_1
├── src
└── lambdas
├── tsconfig.json
└── serverless.yml
└── service_2
├── src
└── lambdas
├── tsconfig.json
└── serverless.yml
├── serverless.yml
├── tsconfig.json
└── package.json
Earlier inside service_1 and service_2 there were independently package.json, but now my project has become bigger.
What I'm trying to do is to make only one global node_modules for whole project.
I've pipeline build for my project in few stages.
e.g. for main build is code below:
phases:
install:
runtime-versions:
nodejs: 14
commands:
- npm install -g serverless#2.66.2
- npm i
build:
commands:
- sls deploy --force --stage $ENV_NAME
for services the same code but only need to be added:
build:
commands:
- cd services/service_1
- sls deploy --force --stage $ENV_NAME
So for each build we have an issue to run "npm i" and that's a problem. I want to avoid duplicated "npm i" per build and have installed all packages in first build and somehow make my "node_modules" shared for all next function that'll be installed in next builds.
I've read that in serverless there are "layers" to create some shared folder for node_modules and just make a reference for each lambda to use it.
How is it possible to run "npm i" only in first build and create a reference for each functions that is inside service_1 and service_2?
I understand that inside each service/serverless.yml for each function I need to add layers. But I don't understand how to set global layer for all functions in first build.
The code below is in each service/serverless.yml
layers:
NodeLayer:
path: ../../layers
name: node-layer-${self:provider.stage}
function:
myLambdaFunc:
handler: src/lambdas.myLambdaFunc
layers:
- { Ref: NodeLayerLambdaLayer }