How can I create a second sub collection in Avone theme?

Good day,

Can anybody please advise me on the following.

I am using the Avone theme in shopify. I want to know if i can create a second sub collection in shopify.

To give an example - my main collection is Fittings. From there you will get Quick release fittings. then from there you choose poly prop or Aluminium.

At this stage I only have 3 pages to drop down in. (if I can call it that)

Can I do that with code? and if so does anybody know the code I need. I tried to make a collection template when customizing my store but - it doesn’t give me the option to make another collection template.

You can do that by adding sub-collections to your main collection menu item in your Online store > Themes > Navigations

Thank you. I tried that. It doesnt work.

So this is the first one. Fittings - that will show quick release fittings

f i go into quick release fittings - all the fittings is in there all mixed up like this.

I want to on this page have another split where i can then put in Aluminium or poly prop