How do I add a collection into the left side bar

Hi I’m new to Shopify, so sorry if this seems very basic. But in my side navigation, how do I have a section for men’s perfumes and one for women’s perfumes? I have collections for each of these are in my main menu. But how do I get them to be in the sidebar so when viewing all perfumes or a particular brand people can sort by women’s or men’s?

This is what’s in my sidebar at the moment - https://luxefragrances.com.au/collections/giorgio-armani

i used the Search & Discovery app to get brands to load in the side bar

depends on your theme but in most cases the shopify search and discovery app will allow you to add these filters on the left hand side. you will first need to create metafields and assign all products to these values that you want and then go to search and discovery app and set it up

You can add this from the app. So go to the app interface and create a new filter, i believe it should let you add new filters based on your collections else you might have to use metafields

i did as you said, however how can i populate this field in bulk? must i do it through a full product export, add it to the csv then import the csv or can i do it in the dashboard in bulk?

yes. go to products, export, open in excel or google sheets, update them and re-import